Citation
Background Paper 2: Case Studies of Medical Technologies: Case Study 12

Material Information

Title:
Background Paper 2: Case Studies of Medical Technologies: Case Study 12 Assessing Selected Respiratory Therapy Modalities: Trends and Relative Costs in the Washington, D.C., Area
Series Title:
The Implications of Cost-Effectiveness Analysis of Medical Technology
Creator:
United States. Congress. Office of Technology Assessment.
Scheffler, Richard M.
Delaney, Morgan
Publisher:
U.S. Congress. Office of Technology Assessment
Publication Date:
Language:
English
Physical Description:
viii, 23 p. ; 28 cm.

Subjects

Subjects / Keywords:
Respiratory therapy ( LCSH )
intermittent positive pressure breathing ( KWD )
alternative respiratory therapy modalities ( KWD )
Cost effectiveness ( LCSH )
cost of treatments ( KWD )
Genre:
federal government publication ( marcgt )

Notes

General Note:
A case study requested by the Office of Technology Assessment (OTA) that presents "a brief overview of selected respiratory therapy modalities, including an assessment, drawn from the available medical and scientific literature, of what is known about the efficacy or effectiveness of various respiratory therapy procedures" (p. 3).
General Note:
Original is missing pages 1-2.

Record Information

Source Institution:
University of North Texas
Holding Location:
University of North Texas
Rights Management:
This item is a work of the U.S. federal government and not subject to copyright pursuant to 17 U.S.C. §105.

Aggregation Information

IUF:
University of Florida
OTA:
Office of Technology Assessment

Downloads

This item is only available as the following downloads:


Full Text

PAGE 1

Assessing Selected Respiratory Therapy Modalities: Trends and Relative Costs in the Washington, D.C., Area July 1981 NTIS order #PB82-101122

PAGE 2

CASE STUDY #12 THE IMPLICATIONS OF COST-EFFECTIVENESS ANALYSIS OF MEDICAL TECHNOLOGY JULY 1981 BACKGROUND PAPER #2: CASE STUDIES OF MEDICAL TECHNOLOGIES CASE STUDY #12: ASSESSING SELECTED RESPIRATORY THERAPY MODALITIES: TRENDS AND RELATIVE COSTS IN THE WASHINGTON, D. C., AREA Richard M. Scheffler, Ph. D. Visiting Associate Professor of Health Economics School of Public Health, University of California, Berkeley Morgan Delaney, M.D. Assistant Professor of Medicine, Department of Medicine George Washington University Hospital, Washington, D.C. OTA Background Papers are documents that contain information believed to be useful to various parties. The information undergird formal OTA assessments or is an outcome of internal exploratory planning and evaluation. The material is usually not of immediate policy interest such as is contained in an OTA Report or Technical Memorandum, nor does it present options for Congress to consider.

PAGE 3

. Library of Congress Catalog Card Number 80-600161 For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402

PAGE 4

Foreword This case study is one of 17 studies comprising Background Paper #2 for OTAs assessment, The Implicatiom of Cost-Effectiveness Analysis of Medical Technology. That assessment analyzes the feasibility, implications, and value of using cost-effectiveness and cost-benefit analysis (CEA/CBA) in health care decisionmaking. The major, policy-oriented report of the assessment was published in August 1980. In addition to Background Paper #2, there are four other background papers being published in conjunction with the assessment: 1) a document which addresses methodological issues and reviews the CEA/CBA literature, published in September 1980; 2) a case study of the efficacy and cost-effectiveness of psychotherapy, published in October 1980; 3) a case study of four common diagnostic X-ray procedures, to be published in summer 1981; and 4) a review of international experience in managing medical technology, published in October 1980. Another related report was published in September of 1979: A Review of Selected Federal Vaccine and Immumnization Policies. The case studies in Background Paper #2: Case Studies of Medical Technologies are being published individually. They were commissioned by OTA both to provide information on the specific technologies and to gain lessons that could be applied to the broader policy aspects of the use of CEA/CBA, Several of the studies were specifically requested by the Senate Committee on Finance. Drafts of each case study were reviewed by OTA staff; by members of the advisory panel to the overall assessment, chaired by Dr. John Hogness; by members of the Health Program Advisory Committee, chaired by Dr. Frederick Robbins; and by numerous other experts in clinical medicine, health policy, Government, and economics. We are grateful for their assistance. However, responsibility for the case studies remains with the authors. Il l

PAGE 5

Advisory Panel on The Implications of Cost-Effectiveness Analysis of Medical Technology John R. Hogness, Panel Chairman President, Association of Academic Health Centers Stuart H. Altman Sheldon Leonard Dean Manager Florence Heller School Regulatory Affairs Brandeis University General Electric Co, James L. Bennington Chairman Department of Anatomic Pathology and Clinical Laboratories Childrens Hospital of San Francisco John D. Chase Associate Dean for Clinical Affairs University of Washington School of Medicine Joseph Fletcher Visiting Scholar Medical Ethics S C hool of Medicine University of Virginia Clark C. Havighurst Professor of Law School of Law Duke University Barbara J. McNeil Department of Radiology Peter Bent Brigham Hospital Robert H. Moser Executive Vice President American College of Physicians Frederick Mosteller Chairman Department of Biostatistics Harvard University Robert M. Sigmond Advisor on Hospital Affairs Blue Cross and Blue Shield Associations Jane Sisk Willems VA Scholar Veterans Administration

PAGE 6

OTA Staff for Background Paper #2 Joyce C. Lashof, Assistant Director, OTA Health and Life Sciences Division H. David Banta, Health Program Manager Clyde J. Behney, Project Director Kerry Britten Kemp, Editor Virginia Cwalina, Research Assistant Shirley Ann Gayheart, Secretary Nancy L. Kenney, Secretary Martha Finney, Assistant Editor Other Contributing Staff Bryan R. Luce Lawrence Miike Michael A. Riddiough Leonard Saxe Chester Strobel OTA Publishing Staff John C. Holmes, Publishing Officer John Bergling* Kathie S. Boss Debra M. Datcher Patricia A. Dyson* Mary Harvey* Joe Henson

PAGE 7

Preface This case study is one of 17 that comprise Background Paper #2 to the OTA project on the Implications of Cost-Effectiveness Analysis of Medical Technology. The overall project was requested by the Senate Committee on Labor and Human Resources. In all, 19 case studies of technological applications were commissioned as part of that project. Three of the 19 were specifically requested by the Senate Committee on Finance: psychotherapy, which was issued separately as Background Paper #3; diagnostic Xray, which will be issued as Background Paper #5; and respiratory therapies, which will be included as part of this series. The other 16 case studies were selected by OTA staff. In order to select those 16 case studies, OTA, in consultation with the advisory panel to the overall project, developed a set of selection criteria. Those criteria were designed to ensure that l l l l l l l as a group the case studies would provide: examples of types of technologies by function (preventive, diagnostic, therapeutic, and rehabilitative): examples of types of technologies by physical nature (drugs, devices, and procedures); examples of technologies in different stages of development and diffusion (new, emerging, and established); examples from different areas of medicine (such as general medical practice, pediatrics, radiology, and surgery); examples addressing medical problems that are important because of their high frequency or significant impacts (such as cost ); examples of technologies with associated high costs either because of high volume (for low-cost technologies) or high individual costs; examples that could provide informative material relating to the broader policy and methodological issues of cost-effectiveness or cost-benefit analysis (CEA/CBA); and l examples with sufficient evaluable literature. On the basis of these criteria and recommendations by panel members and other experts, OTA staff selected the other case studies. These 16 plus the respiratory therapy case study requested by the Finance Committee make up the 17 studies in this background paper. All case studies were commissioned by OTA and performed under contract by experts in academia. They are authored studies. OTA subjected each case study to an extensive review process. Initial drafts of cases were reviewed by OTA staff and by members of the advisory panel to the project. Comments were provided to authors, along with OTAs suggestions for revisions. Subsequent drafts were sent by OTA to numerous experts for review and comment. Each case was seen by at least 20, and some by 40 or more, outside reviewers. These reviewers were from relevant Government agencies, professional societies, consumer and public interest groups, medical practice, and academic medicine. Academicians such as economists and decision analysts also reviewed the cases. In all, over 400 separate individuals or organizations reviewed one or more case studies. Although all these reviewers cannot be acknowledged individually, OTA is very grateful for their comments and advice. In addition, the authors of the case studies themselves often sent drafts to reviewers and incorporated their comments. These case studies are authored works commissioned by OTA. The authors are responsible for the conclusions of their specific case study. These cases are not statements of official OTA position. OTA does not make recommendations or endorse particular technologies. During the various stages of the review and revision process, therefore, OTA encouraged the authors to present balanced information and to recognize divergent points of view. In two cases, OTA decided that in order to more fully present divergent views on particular technologies a commentary should be added to the case study. Thus, following the case

PAGE 8

studies on gastrointestinal endoscopy and on the Keyes technique for periodontal disease, commentaries from experts in the appropriate health care specialty have been included, followed by responses from the authors. The case studies were selected and designed to fulfill two functions. The first, and primary, purpose was to provide OTA with specific information that could be used in formulating general conclusions regarding the feasibility and implications of applying CEA/CBA in health care. By examining the 19 cases as a group and looking for common problems or strengths in the techniques of CEA/CBA, OTA was able to better analyze the potential contribution that these techniques might make to the management of medical technologies and health care costs and quality. The second function of the cases was to provide useful information on the specific technologies covered. However, this was not the major intent of the cases, and they should not be regarded as complete and definitive studies of the individual technologies. In many instances, the case studies do represent excellent reviews of the literature pertaining to the specific technologies and as such can stand on their own as a useful contribution to the field. In general, though, the design and the funding levels of these case studies were such that they should be read primarily in the context of the overall OTA project on CEA/CBA in health care. Some of the case studies are formal CEAs or CBAs; most are not. Some are primarily concerned with analysis of costs; others are more concerned with analysis of efficac y or effectiveness. Some, such as the study on end-stage renal disease, examine the role that formal analysis of costs and benefits can play in policy formulation. Others, such as the one on breast cancer surgery, illustrate how influences other than costs can determine the patterns of use of a technology. In other words, each looks at evaluation of the costs and the benefits of medical technologies from a slightly different perspective. The reader is encouraged to read this study in the context of the overall assessments objectives in order to gain a feeling for the potential role that CEA/CBA can or cannot play in health care and to better understand the difficulties and complexities involved in applying CEA/CBA to specific medical technologies. The 17 case studies comprising Background Paper #2 (short titles) and their authors are: Artificial Heart: Deborah P. Lubeck and John P. Bunker Automated Multichannel Chemistry Analyzers: Milton C. Weinstein and Laurie A. Pearlman Bone Marrow Transplants: Stuart O. Schweitzer and C. C. Scalzi Breast Cancer Surgery: Karen Schachter and Duncan Neuhauser Cardiac Radionuclide Imaging: William B. Stason and Eric Fortess Cervical Cancer Screening: Bryan R. Luce Cimetidine and Peptic Ulcer Disease: Harvey V. Fineberg and Laurie A. Pearlrnan Colon Cancer Screening: David M. Eddy CT Scanning: Judith L. Wagner Elective Hysterectomy: Carol Korenbrot, Ann B. Flood, Michael Higgins, Noralou Roos, and John P. Bunker End-Stage Renal Disease: Richard A. Rettig Gastrointestinal Endoscopy: Jonathan A. Showstack and Steven A. Schroeder Neonatal Intensive Care: Peter Budetti, Peggy McManus, Nancy Barrand, and Lu Ann Heinen Nurse Practitioners: Lauren LeRoy and Sharon Solkowitz Orthopedic Joint Prosthetic Implants: Judith D. Bentkover and Philip G. Drew Periodontal Disease Interventions: Richard M. Scheffler and Sheldon Rovin Selected Respiratory Therapies: Richard M. Scheffler and Morgan Delaney These studies will be available for sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402. Call OTAs Publishing Office (224-8996) for availability y and ordering information.

PAGE 9

Case Study #12 Assessing Selected Respiratory Therapy Modalities: Trends and Relative Costs in the Washington, D. C., Area Richard M. Scheffler, Ph.D. Visiting Associate Professor of Health Economics* School of Public Health University of California, Berkeley Morgan Delaney, M.D. Assistant Professor of Medicine Department of Medicine George Washington University Hospital Washington, D.C. AUTHORS ACKNOWLEDGMENTS We are grateful to Dr. Louise Russell of The Brookings Institution for helpful comments on an earlier draft of this paper. We would also like to thank Lynn Herman for her help in collecting and processing the data and Robert Friedland for his computer programing assistance. l On leave from Department of Economics, George Washington University, Washington, D.C.

PAGE 10

Contents Page Introduction . . . . . . . . . . . . . 3 RespiratoryTherapy: A Definition. . . . . . . . . . 4 The Organization and Delivery of RespiratoryTherapyServices . . . s An Assessment of Respiratory Therapy Services . . . . . . 5 OxygenTherapy . . . . . . . . . . . 6 Aerosol Therapy. .......,.. . . . . . . . . . 6 Physical Therapy . . . . . . . . . . . 7 Mechanical Aids to Lung Inflation, . . . . . . . . 7 A Survey of Hospital-BasedRespiratory Therapy intheWashington, D.C., SMSA 10 Survey Methods and Procedures . . . . . . . . 10 Survey Results: Hospital Utilization of Respiratory Therapy. . . . 11 Estimates of the Relative Costs of RespiratoryTreatment Modalities . . 14 Conclusions and Implications. . . . . . . . . . . 17 Appendix: Questionnaire Used in the Washington, D.C., SMSA Respiratory Therapy Department Survey . . . . . . . . . 19 References . . . . . . . . . .......;. . . ~ LIST OF TABLES Table No. Page l. Utilization of Respiratory Therapy by Hospital Ownership, 1979. . . 12 2. Utilization of Respiratory Therapy by Hospital Bed-Size, 1979. . . . 13 3. Trends in the Utilization of Four RespiratoryTherapyTreatment Modalities, 4. 5. 6. 1976-79 . . . . . .: ...;..... . . . . . 13 Personnel Used To Deliver Various Respiratory Therapy Treatrnent. . . 15 Modal Time Required by a Respiratory TherapistorTechnician To Deliver Various Respiratory Therapy Treatments . . . . . . . 15 Estimates of Relative Costs and Charges for Four RespiratoryTherapy Treatment Modalities . . . . . . . . . . . . . l6

PAGE 11

Case Study #12: Assessing Selected Respiratory Therapy Modalities: Trends and Relative Costs in the Washington, D. C., Area Richard M. Scheffler, Ph.D. Visiting Associate Professor of Health Economics School of Public Health University of California, Berkeley Morgan Delaney, M.D. Assistant Professor of Medicine Department of Medicine George Washington University Hospital Washington, D.C. INTRODUCTION There are data that suggest that some 25 to 30 percent of all patients admitted to hospitals in the 1970s received respiratory therapy. l Intermittent positive pressure breathing (IPPB)the active inflation of the lungs during inspiration under positive pressure from a cycling valve was delivered to more than one-fourth of these patients, making IPPB the single largest respiratory treatment modality (method of therapy) (16). 2 Utilization of respiratory therapy in U.S. hospitals has been estimated to have cost about $700 million in 1975, or more than $1 billion in 1979 dollars (16). 3 A lay persons definition of the term respiratory therapy is presented in the next part of this case study. Following that is a description 1 According to Louise Russell (31 ), this compares to about 10 percent of all hospital admissions in 1961-62 and 19 percent in 1966-67. From a national sample of 750 U.S. non-Federal short-term hospitals, about 8 percent of all hospital admissions received IPPB (13). 3 The $1 billion estimates assumes the 1975 estimate made by Russell (16) and adjusts it only for the average increase in medical care prices over the 1975-79 period of about 4 S percent. of how the delivery of respiratory therapy is currently organized in the hospital sector. Next is presented a brief overview of selected respiratory therapy modalities, including an assessment, drawn from the available medical and scientific literature, of what is known about the efficacy or effectiveness of various respiratory therapy procedures. 4 These procedures are divided into four basic categories: 1) oxygen therapy, 2) aerosol therapy, 3) physical therapy, and 4) mechanical aids to lung inflation. The descriptive material presented in this case study is not a totally exhaustive or definitive review of the literature. Certain topics are discussed in detail, while others are mentioned only briefly. Special attention is paid to IPPB, both because it is one of the most frequently per4 We use the OTA definitions (28) of efficacy and effectiveness. Efficacy: The probability of benefit to individuals in a defined population from a medical technology applied for a given medical problem under ideal conditions of use. Effectiveness. Same as efficacy except that it refers to average conditions of use. 3

PAGE 12

4 Background Paper #2: Case Studies of Medical Technologies formed respiratory therapy procedures and because it has been one of the more controversial ones. Evidence is presented that suggests that in some instances IPPB may be substituted for by alternate treatment modalities. Respiratory therapy practices in the intensive care unit, though an important area of involvement for respiratory therapy personnel, are mentioned only briefly. The fifth part of this case study presents the results of a survey we conducted of current respiratory therapy practices by hospitals in the Washington, D. C., Standard Metropolitan Statistical Area (SMSA) during 1979. Particular emphasis was placed on data concerning the use of IPPB and other modalities which can potentially be substituted for IPPB. We were able to obtain data on how often these different treatments were being delivered in the hospitals located in the Washington, D. C., SMSA, and were also able to discern a significant change in the pattern of usage over the past several years. Using the information we collected about the time needed to deliver different types of respiratory therapies, the wages paid to respiratory personnel, and the cost of equipment, in the sixth part of this study, we estimate the relative cost of delivering specific types of treatments. We then compare differences in the relative costs of treatments that can be substituted for one another. Finally, we compare the estimated relative costs to the actual charges for hospitals in our survey. Our analysis presented below supports the conclusion that for some medical indications, alternative treatment modalities, when compared to IPPB, could be delivered at a lower relative cost. Data on efficacy or effectiveness were not collected in our survey. However, our review of the medical literature suggests the comparability of the medical outcomes for some treatments. The implications of the results of our analysis, along with their limitations, are discussed in the concluding section of this study. RESPIRATORY THERAPY: A DEFINITION In general, the term respiratory therapy refers to the medical treatment of a diseased lung. It encompasses all nonsurgical efforts directed at maintaining, improving, or restoring lung function. However, in actual use, the term refers only to those therapeutic interventions carried out by trained respiratory care personnel in accordance with a physicians order. A recent definition of respiratory therapy is the followings Respiratory therapy is an allied health specialty employed with medical direction in the treatment, management, control, diagnostic evaluation, and care of patients with deficiencies and abnormalities of the cardiopulmonar y system. Respiratory therapy shall mean the therapeutic use of the following: medical gases and administration apparatus, environmental control systems, humidification, aerosol, medications, ventilatory support, bronchopulmonary drainage, This definition was approved in 1969 by the Board of Directors of the American Association of Inhalation Therapists (renamed the American Association for Respiratory Therapy in 1972) (8). pulmonary rehabilitation, cardiopulmonary resuscitation, and airway management. Therapeutic respiratory therapy interventions, as noted above, can be grouped into four major categories: 1) oxygen therapy, 2) aerosol therapy, 3) physical therapy, and 4) mechanical aids to lung inflation. The various modalities are defined in greater detail below. Individually or in varying combination, these methods of therapy are being used to treat almost any kind of respiratory problem. They may be used in the general medical and surgical wards, or used in the intensive care unit, where they have been refined into sophisticated and coordinated life support measures. Their use is especially common in patients undergoing surgery involving the chest or upper abdomen and in patients with chronic obstructive bronchial tube diseases, such as emphysema, chronic bronchitis, asthma, and bronchiectasis. Such diseases constituted the sixth leading cause of death in the United States in the 1970s ().

PAGE 13

. Case Study #12 Assessing Selected Respiratory Therapy Modalities Trends and Relative Costs in the Washington D C Area l 5 THE ORGANIZATION AND DELlVERY OF RESPIRATORY THERAPY SERVICES Most U.S. hospitals have developed an organized respiratory therapy department staffed by highly trained and usually certified paramedical personnel. The activities of the paramedical staff are closely supervised by a physician, who serves as the departments medical director. The growth of autonomous respiratory therapy departments within U.S. hospitals, in terms both of total number and size of individual departments, has been substantial and rapid over the past two decades. This growth may be attributed to a number of different factors, including the following: l l l l advances in engineering design since 1950 which have brought about the development of new, highly sophisticated mechanical devices useful in the support of lung function, e.g., mechanical ventilators (breathing machines) (37); increases in the number of patients with acute and chronic respiratory disease, who require respiratory care (22); the need to assure quality control of respiratory care services rendered, by means of effective supervision and ongoing education of workers in the field; and the overall increase in third-party reimbursement in the hospital sector, especially by medicare and medicaid. Respiratory therapy departments may be staffed by personnel of varying levels of formal training (10). A respiratory therapist is usually a graduate of a 2-year hospital or community college program granting an associate degree, which has been approved by the American Medical Association and which is designed to qualify him or her for the registry examination given by the National Board of Respiratory Therapy. By passing that examination, an individual becomes a registered respiratory therapist (R.R.T. ). A respiratory therapy technician completes a l-year hospital-based program combining a curriculum of basic respiratory sciences and supervised clinical experience. By passing the technician certification examination, the individual becomes a certified respiratory therapy technician (C.R.T.T. ). Other personnel employed by respiratory therapy departments include aides, who are trained on the job, and individuals with nursing credentials (R.N. or L.P.N. certification). Despite the distinct differences in formal training among these various types of personnel, the generic term respiratory therapist is often used to refer to any individual involved in the provision of technical respiratory care. The emergence of a formal educational apparatus with mechanisms for achieving professional credentials is fairly recent, and partly because of that, there is considerable blurring of professional role identities. Individuals with limited formal training often possess many years of practical experience which allow them t o assume roles at a higher level of responsibility than their formal training would suggest. 7 By 1976, virtually all large private, nonprofit hospitals (100 beds or more) had developed respiratory therapy departments (31). The recent report of the American Association of Respiratory Therapists concerning job descriptions and salary levels served amply to illustrate this confusion (6). AN ASSESSMENT OF RESPIRATORY THERAPY SERVICES The services offered by respiratory therapy efficacy of specific interventions are made on departments can be conveniently grouped into the basis of the current medical literature. Since four major categories: 1) oxygen therapy, 2) IPPB has been chosen as the major area of inaerosol therapy, 3) physical therapy, and 4) terest in this case study, more attention is mechanical aids to lung inflation. Each of these directed to that than to any of the other inis briefly discussed below. Statements about the terventions.

PAGE 14

6 l Background paper #.2: Case Studies of Medical Technologws Oxygen Therapy The administration of therapeutic gases is one of the more important functions of respiratory therapy. The primary function of the lung is to exchange gas between the atmosphere and the blood (i.e, to take in oxygen and eliminate carbon dioxide (CO 2 ), the waste product of cell metabolism). Many of the diseases that affect the lung can impair its gas exchange capability, resulting in a fall in the oxygen content of the blood. 8 Whether a patient needs supplemental oxygen to restore blood oxygen levels to normal can usually be ascertained by measuring the gas pressures in a sample of the patients blood. If oxygen levels are too low, oxygen is administered to the patient and its supply adjusted by titrating (adjusting) the delivered oxygen concentration. In most instances, the indications for delivery of supplemental oxygen are well established, and there is currently no real controversy concerning when it should be used. A variety of simple devices to deliver varying concentrations of oxygen to a patient are available. Oxygen therapy is one of the oldest of all respiratory therapy modalities, and its effectiveness was established quite early in the treatment of a wide variety of lung diseases (10). Nevertheless, it is possible to identify some serious problems relating to the misuse of oxygen. One problem is that supplemental oxygen is sometimes administered without documentation that the patient has inadequate oxygen in his or her blood. This course of action would be appropriate only under special circumstances (e. g., in an emergency or in the postoperative recovery room). Another problem is that sometimes the patient receiving oxygen is not adequately monitored with respect to the achievement of the desired therapeutic objective (i. e., correction Lung dysfunction results not only from primary lung disease, but also as a byproduct of diseases of other organs. Some degree of lung dysfunction is seen in most hospitalized patients. Thus, oxygen therapy is used by a high percentage of patients who are admitted to a hospital. The need for standardization and coordination of equipment used in oxygen therapy originally led to the development of respiratory therapy departments. Respiratory therapists have usual] y been assigned the role of sampling arterial blood to assess its gas contents, then reportin g these results to the medical team caring for the patient so that appropriate modifications can be made in the amount of oxygen being given to a patient. of the oxygen-deficient state). Sometimes the patient will be given too much oxygen, exposing him or her to potential toxic effects of an overdose of this drug (for indeed, oxygen should be regarded as a drug). Occasionally, a patient is given supplemental oxygen solely because it makes him or her feel better. The issue of psychological benefits v. more objective therapeutic improvements derived from a specific treatment modality is difficult to assess when discussing the scientific efficacy of a therapy. Quite apart from the issues surrounding the misuse of oxygen therapy, it should be noted that additional scientific studies are needed to define more accurately the shortand longterm toxic effects of oxygen when given to patients in higher concentrations than we normally breathe (26). Aerosol Therapy An aerosol is a suspension of very fine particles of a liquid or solid in a gas (e.g., the fog seen on a damp morning is a suspension of water droplets in the air). As such, an aerosol can be breathed into the respiratory tract, where the particles may be deposited and retained. Therapeutic aerosols consist of either water droplets or fine particles of medication added to the inspired air for deposition onto the surface of the lung. Humidity (aerosol of water) and other aerosols are used to achieve four general objectives (10): l l l l humidification of the respiratory tract, wetting of respiratory tract secretions (mucus) so that they can be coughed up more easily, delivery of bronchodilator drugs which dilate the breathing tubes, and administration of antibiotics to treat bronchial infections. Several mechanical devices, which are known as nebulizers, are available to generate an aerosol (i. e., put the particles of water or drug into suspension). These range from a very simple device which depends on a jet of air to create small particles from a liquid to complicated electronic machines, called ultrasonic nebulizers, which create particles by vibrating

PAGE 15

the liquid medium. 9 The aerosol that is generated can be inhaled by the patient without mechanical assistance, or it can be forced into the patients lungs under pressure by a pressurized delivery device such as an IPPB machine. A patient requires instruction by a respiratory therapist in the use of both nebulizers and pressurized delivery devices. Prior to each treatment, the therapist must add the fluid or medication which is to be nebulized to the device. In general, the more complicated the nebulizer used, the greater the degree of supervision required by a respiratory therapist while the patient is using the device. Special circumstances (e.g., a weak or uncooperative patient) ma y necessitate close supervision by a therapist of every treatment. There are currently many controversies relating to the clinical use of aerosol therapy. The indications are not always clear cut, and the effectiveness of a treatment in any given patient has not been satisfactorily defined by scientific studies (26). Also controversial are the choice of type of nebulizer and the need for an IPPB. Many issues remain unresolved, e.g., whether an expensive ultrasonic nebulizer is any more effective than a simple aerosol generator, and whether an IPPB machine is necessary to deliver an aerosol to patients who are breathing on their own (33). Physical Therapy Physical therapy for patients with lung disease has two basic objectives: to facilitate the removal of secretions from the lungs, and l to improve the efficiency of breathing. Among the physical measures employed are: 1) percussion (clapping) and vibration of the thorax, 2) postural draining (positioning the patient so that secretions will drain toward the mouth under the influence of gravity), and 3) breathing exercises to teach a patient how to use his or her respiratory muscles more efficiently. For more detailed description of the technical aspects of the various types of nebulizers, the reader should consult one of the standard textbooks of respiratory care, e.g., that by Egan ( 10). Although these procedures enjoy widespread acceptance throughout the United States and the worldindeed, many hospitals have established autonomous chest physiotherapy departmentsthere is a dearth of well-controlled scientific evidence to support their effectiveness. In many instances, a spontaneous cough could yield the same amount of expectorated sputum as the bronchial drainage procedures employed by the chest physiotherapist (9). For example, although chest physiotherapy is often routinely ordered for patients with uncomplicated pneumonia, these patients are usually quite capable of coughing themselves and can effectively clear excess secretions from their respiratory tracts. Few scientific studies have adequately demonstrated that chest physiotherapy aids patients in the recovery from lung diseases (24). Many additional well-planned and well-controlled studies will be necessary to answer the many questions in this area. Mechanical Aids to Lung Inflation Mechanical aids to lung inflation are those interventions used to support the ventilator function of the respiratory system, This functionbulk movement of air from the environment through the breathing tubes to the gasexchange membrane deep in the lungsis normally accomplished by the bellows-like action of the muscles of respiration acting upon the lungs. A variety of mechanical ventilators which are capable of pumping air into the lungs have been developed. Most of them are electrically powered and generate positive pressure which forces air into the lungs at rhythmic intervals. If a patients breathing has totally ceased owing to suppression of brain activity (e. g., following an overdose of sleeping pills), me chanical ventilator support is necessary to sustain the patients life. Mechanical ventilator support may be similarly useful for patients with paralysis of the respiratory muscles, chest wall injury, and acute and potentially reversible lung disease, such as extensive pneumonia or smoke inhalation, Its effectiveness in these instances is well-accepted. Life support of a critically ill patient requires a coordinated team

PAGE 16

8 l Background Paper #2 Case Studies of Medical Technologies effort involving a physician, nurse, respiratory therapist, and other paramedical personnel. The patient is best monitored in an intensive care unit where equipment and resources can be concentrated and made readily available. Most respiratory therapy departments are intimately involved in the delivery of critical care, and involvement in this area constitutes one of their major activities. The most highly trained and experienced therapists work in this area. Some people have advocated the use of mechanical breathing machines for purposes other than life support of critically ill patients. One of these, mentioned in the discussion of aerosol therapy above, is the use of an IPPB machine to facilitate delivery of an aerosol into a patients lungs. The acronym IPPB has now become virtually synonymous with this use and is only rarely used to refer to long-term continuous mechanical ventilator support. Thus, IPPB treatment refers to the use of a pressurized ventilator to deliver a gas with humidity and/or other aerosols to a spontaneously breathing patient for periods of 10 to 20 minutes each, usually several times a day (1). IPPB treatments have been one of the more controversial areas in the respiratory field. Therefore, a more detailed discussion of the proposed indications for and the arguments concerning the efficacy of IPPB is presented below. IPPB therapy has been based on the principal assumption that the mechanical breathing machine will deliver a larger breath than the patient is able to take spontaneously with less physical effort from the patient (17). Several objectives for the use of IPPB have been developed. These include (1): l l improving the delivery of aerosol medications to those patients who are unable to take a deep breath or whose pattern of breathing is not regular; improving the overall level of breathing where it is inadequate to meet the bodys metabolic requirements (i. e., when not all the CO Z is being excreted by the patients lungs); l l improving cough and expectoration of respiratory tract secretions (effective cough is dependent on a deep inspiration prior to the cough itself); and preventing collapse of lung segments in patients who cannot take deep breaths (e.g., in the postoperative patients whose respirations are hindered by residual anesthetic agents, drugs or medications, and pain). Although these indications for the use of IPPB are widely accepted, very few scientific data have been collected to support its efficacy (38). Moreover, IPPB therapy was introduced and became widespread before its scientific validity had been rigorously tested. In 1974, the available information about IPPB, as well as all other respiratory therapy modalities, was reviewed at the Conference on the Scientific Basis of Respiratory Therapy, held at Sugarloaf, Pa. That 1974 conference was a benchmark consensus conference sponsored by the National Institutes of Health (NIH). Although it focused on an assessment of the efficacy of respiratory therapy in the treatment of patients with stable chronic obstructive lung disease, it also considered the overall use of respiratory therapy. Conferees judged the majority of studies of clinical effectiveness of IPPB published up until that time to be inadequate investigations, often not well designed from a scientific or statistical standpoint (9), They also recommended additional scientific studies that would attempt to determine whether IPPB has more than transient effects in any group of patients (29). Since 1974, there have been a number of editorials and papers, many highly emotional, restating the IPPB controversy, but offering very little new information (14,16,25). The total number of investigations published every year on the subject of IPPB has actually declined (27). An attempt to draw conclusions from the available studies of IPPB is difficult, because many of the studies were not well-designed. Many do not use comparable patient populations or methods of delivering IPPB (e.g., studies attempting to compare IPPB with alternative treatment modalities often use different

PAGE 17

endpoints or outcomes as indicators of successful results). For delivery of aerosol medications, IPPB has been compared to a number of other delivery modes. In seven of eight studies published since 1953, a simple nebulization device was found to be just as effective as an IPPB machine in delivering an aerosol medication (12,13,15,21,23, 30,36); the eighth report found IPPB to be better (34). Given this apparent similarity of efficacy between devices, considerations other than efficacy might be used to dictate the choice of treatment modality. The evidence yielded by studies on the effectiveness of IPPB for improving the overall level of ventilation (5,11,19,20,35) is difficult to assess because of problems with the study designs. A review of the various studies suggests that any improvement in ventilation brought about by IPPB treatment is usually transient, being essentially limited to the duration of the treatment. One study found that the same level of intermittent improvement in breathing could be achieved if the patient were required to voluntarily hyperventilate for several minutes (33). At many hospitals, a routine of delivering four approximately 20-minute treatments per day has evolved. There is no satisfactory evidence to show that improving a patients breathing for 1 hour each day will have any significant overall effect on that patients clinical course. Few, if any, data exist on the issue of long-term benefits (26). A third accepted indication for IPPB use is in the prevention of lung collapse, especially in the postoperative period when the patient may not be able to take deep breaths. However, the majority of studies fail to show measurable benefit from this use of IPPB (3,4,32). For improving lung inflation, IPPB has been compared in other studies to two other mechanical devices: 1) blow bottles (which require the patient to move water from one bottle to another by generating high pressures in the system when the patient blows into it), and 2) the incentive spirometer (which requires the patient to generate a negative pressure in the system by deep inspiration, thus raising a plastic ball in the vacuum created). Both of these other devices have been claimed to be more effective than IPPB in preventing postoperative lung collapse. One study found a complication rate of 30 percent in patients receiving IPPB, 15 percent in patients using the incentive spirometer, and 8 percent in those using blow bottles (18). These results certainly raise doubts about the continued exclusive use of IPPB in the prevention of lung collapse, Significant unanswered questions about the efficacy of IPPB remain, and the need for more scientific studies is great. Despite the overall dearth of information, however, the evidence we have reviewed suggests that IPPB may be no more effective than various other treatment modalities in achieving specific therapeutic goals. In delivering a therapeutic aerosol to a patient, an IPPB machine seems to be no more effective than an ultrasonic nebulizer or a simple aerosol generator. In preventing postoperative lung collapse, IPPB would appear to be no more effective than the simply designed incentive spirometer. A second Conference on the Scientific Basis of Respiratory Therapy, sponsored by the National Heart, Lung, and Blood Institute of NIH, was held in Atlanta, Ga., on November 14-16, 1979. The conference program was limited to a discussion of in-hospital, nonintensive care respiratory therapy. Intensive care respiratory therapy was specifically excluded. Because of the highly specialized equipment and techniques employed in a total life support setting, intensive care respiratory therapy was regarded as worthy of being the topic of a separate conference. Conferees at the 1979 conference discussed a broad array of topics under the same four general categories which have been used in this case study: oxygen therapy, aerosol therapy, physical therapy, and mechanical aids to lung inflation. Their reports sought to define what was known and what was not known, and to recommend what additional studies should be undertaken. A brief overview of the 1979 Atlanta conference proceedings, which will be published in their entirety, is presented below.

PAGE 18

In 1979, many issues highlighted by the 1974 Sugarloaf conference on respiratory therapy, still remained unresolved. A recurring theme throughout the 1979 conference was that the lack of proof of a procedures efficacy does not equate with no efficacy at all. Most procedures have been empirically derived. Many have a long history of use in the realm of folk medicine, with at least subjective benefit derived by the patient being treated. The application of rigid scientific analysis to study the mechanism of action and measurement of objective outcome achieved by these procedures has come to the forefront only within the past several decades. Whether a procedure which is at least not harmful to the patient, and possibly quite beneficial, should be withheld pending the final outcome of scientific studies which may take many years to complete to anyones satisfaction remains to be answered. The major issues regarding oxygen therapy in 1979 were basically the same issues discussed in 1974: misuse of the drug, effective monitoring of its therapeutic success, and a need for better understanding of its toxicities. Conferees noted that the efficacy of the drug in relieving acute hypoxemia (oxygen deficiency) is beyond dispute. However, with regard to chest physiotherapy measures, conferees noted, a great deal of fundamental information concerning their effectiveness is lacking. There is a need to define more precisely what the various techniques are and to define standards for them (e. g., standards concerning the performance of chest vibration). In the discussion of aerosol therapy, conferees directed their attention to the lack of information about what constitutes an adequate aerosol for penetration of the lung. The size of the aerosol particle created may be of some importance. There is little information available on A SURVEY OF HOSPITAL-BASED WASHINGTON, D. C., SMSA Survey Methods and Procedures In order to estimate the relative costs of IPPB the mechanism of action of aerosols at the cellular level and the effects aerosols bring about. Additionally, it is not clear which parameters can or should be measured to assess whether an aerosol has had any effect. Until such knowledge has been accumulated, conferees suggested, no definitive conclusions can be drawn about the choice of the device used to generate an aerosol. The final topic of discussion at the 1979 conference was mechanical aids to lung inflation. Once again, the lack of basic information about both the theory and practice pertaining to this type of respiratory care was noted. To establish the comparative efficacy of the various aids IPPB v. incentive spirometry v. deep breathingconferees recommended additional studies with standardized endpoints and precise definition of terms. They felt that the potential benefits of such aids must be established before meaningful cost-benefit studies could be undertaken. Any attempt to draw overall conclusions about whether respiratory therapy itself is efficacious is faced by formidable obstacles. Too many pieces of scientific evidence are unavailable at this time. Conferees suggested that continued research in this area is clearly warranted. Data we collected on the utilization of selected respiratory therapy modalities among the hospitals in Washington, D. C., SMSA in 1979 are presented in the next part of this case study. The subsequent part contains our estimates of the relative costs of delivering an aerosol medication by three different devices: an IPPB machine, an ultrasonic nebulizer, and a simple aerosol generator, Also compared are the relative costs of using an IPPB v. an incentive spirometer to improve lung inflation. RESPIRATORY THERAPY IN THE and those treatment modalities which are potential substitutes, it was necessary for us to develop a new data base including the utiliza-

PAGE 19

tion of different treatment modalities, their relative cost, and the personnel employed by different sizes and types of hospitals. This information is not currentl y available for multiple hospitals on a systematic basis. 10 We selected as our geographic survey area the Washington, D. C., SMSA. This SMSA has a population of over 3 million (making it the seventh largest SMSA in the United States), and it includes a total of 56 hospitals. Using the 1978 guide issue of the American Hospital Association, we located each hospital in the Washington, D. C., SMSA and recorded data on hospital ownership, control, size (in terms of number of beds), yearly admissions, and occupancy rates. We then designed and pretested a questionnaire on seven sample hospitals. In the pretest, data were collected via phone interviews with the technical directors (chief therapists) of respiratory therapy units. After the pretest, the questionnaire was revised and mailed to the technical or medical director of the respiratory therapy department at each of the 56 hospitals in the Washington, D. C., SMSA. Of the 56 hospitals in the survey universe, 43 provided some type of respiratory therapy. These 43 hospitals were contacted between July and September of 1979. For the overall utilization data on respiratory therapy in these hospitals, the response rate was about 60 percent For some specific data items, the response rate may have been lower. 12 Of the 43 hospitals that provide respiratory therapy in the Washington, D. C., SMSA, 7 5 percent are private (60 percent private nonprofit, 15 percent private for-profit) and 25 percent are governmental (15 percent non-Federal governmental and 10 percent Federal). Approximately 31 percent have some type of teaching affiliation. Twenty-seven percent of the 43 hospitals surveyed have up to 150 beds, 15 percent have 151 to 250 beds, 32 percent have 251 to 450 beds, and 26 percent have more than 450 beds. 13 In order to provide some time-trend data o n the utilization of four major treatment modalities used in delivering respiratory therapy, we also conducted a special survey of five teaching hospitals in the Washington, D. C., SMSA. These hospitals provided data from their records for the 1976-79 period on the following four modalities: 1) IPPB, 2) ultrasonic nebulization, 3) simple aerosol, and 4) incentive spirometry. These hospitals were large (averaging over 600 beds) and all had some teaching affiliation. Survey Results: Hospital Utilization of Respiratory Therapy The results of the survey of Washington, D. C., SMSA hospitals shown in table 1 indicate that 44 patients per 100 hospital admissions per month received some type of respiratory therapy On the average, for all reporting hospitals, 723 respiratory therapy treatments were delivered per 100 hospital admissions. Governmental hospitals (Federal and non-Federal) delivered less than one-fourth the average number of respiratory treatments per 100 admissions for all reporting hospitals. A qualitative judgment of the appropriateness of these different utilization rates is not possible without data on the case mix and health status of the patient population treated. In part, the differences may reflect factors such as lack of equipment or the quantity and training of the staff. At private for-profit hospitals, IPPB was delivered to 12 patients per 100 admissions, about twice the average rate for all hospitals in the sample. For all hospitals in the sample, an average of 60 IPPB treatments were delivered per 100 patient admissions. Private for-profit hospitals, at 190 IPPB treatments per 100 patient admissions, were significantly above the iT[) our knowledge, t)ur data are the ~)nl}. sy~terna tlcally cL)l ]ected data {ln the cost, c hdrge~ ut iilzati(ln, and per~(lnne[ used In h(mpltal -bad retpl rat t~ry therapy departments. lJ5]ng t and chi -squ~re te~ts on the average \Ize <)1 the h<)spltal and ownership of report]n~ and nt)nreportln~ ho~pltals w e find n~l systematic bias. 12A statistical test 01 the r(prcsent~~t]icn[>s< ot each ~pec]tlc data item was n t) t te~~ible WI t h I n t ht> I r-a mew(lrk (It ~)ur data c (l] lec t lo n

PAGE 20

Table l. Utilization of Respiratory Therapy by Hospital Ownership, 1979 a (per 100 admissions per month) Governmental Private Federal Non-Federal Nonprofit For-profit All hospitals Total patients treated with respiratory therapy . . . 46 55b 41 44 N= 4 N= 2 N= 4 N= 1 N= 11 Total respiratory therapy treatments . . . . . 153 180 b 830 c 723 N= 4 N= 2 N = 17 N= l N =24 IPPB patients. . . . . . . . . . . 3 3b 7 12 6 N= 3 N= 2 N = 19 N= 5 N =29 IPPB treatments . . . . . . . . . 11 27b 79 190 60 N= 4 N= 2 N =24 N= 7 N =37 Incentive spirometry patients . . . . . . 12 l2 b 12 7 11 N= 3 N= 2 N = 19 N= 5 N =29 Chest physical therapy treatments. . . . . . 63 32b 130 130 66 N= 3 N= 2 N = 15 N= 5 N =25 N = numt)er O( responding hospitals aBased on hospitals (n the Washington, D c SMSA bBeCause of the small number of observations In these cateaor(es, these data should be used With caut~on clnsufflc lent obs.watlons mean, followed by private nonprofits, at 79 treatments per 100, The number of IPPB treatments delivered per 100 admissions at Federal and non-Federal Government hospitals was below the average for all hospitals in the sample. Combining the data on the patients treated with IPPB and the number of IPPB treatments, we estimate that, on average, 10 IPPB treatments are given to each patient receiving IPPB. 17 Incentive spirometry was used by about 11 patients per 100 patient admissions, except at private for-profit hospitals, where the figure was 7 per 100 patient admissions. The number of chest physical therapy treatments averaged about 66 per 100 admissions, although Federal and non-Federal Government hospitals had a far lower utilization rate than private for-profit and nonprofit hospitals. Although the data in table 1 suggest differences between for-profit hospitals and other hospitals patterns of usage of respiratory treatment modalities, the reasons for these differences are unclear .16 Many of the for-profit hospitals in the Washington, D. C,, SMSA are small, do not have teaching affiliations, and lack the equipment and staff necessary to debin 1973, one study estimatecf the number of IPPB treatments to be 236 per 100 patient admissions per month for 123 reporting hospitals (2). t 7U5ua]ly, t his wc~uld mean I our treatments a day for 2 L z daYs, I Hwe are ~ra tefu] tcl LCJU ise Russell of The Brookings Institution for suggest ing this point. liver respiratory therapy. For-profit hospitals may have a somewhat different patient mix, and the physicians ordering respiratory therapy treatments in these institutions may not have the benefit of consultation with lung specialists. Moreover, the indication for employing a specific respiratory modality is rarely documented in the medical records. Respiratory therapy departments at these and other hospitals do not document why specific treatments are given. Table 2 shows the data we collected on the utilization of respiratory therapy by hospitals of different bed-size categories. It is interesting to observe that hospitals with more than 450 beds delivered about 25 IPPB treatments per 100 patient admissions, as compared to the average of 60 per 100 admissions for all hospitals in the sample. Moreover, the percentage of patients receiving IPPB treatments is inversely related to hospital bed-size. 20 Compared to the other hospitals in the sample, hospitals with 150 to 250 beds have more patients per 100 admissions receiving incentive spirometry (30 per 100 admissions), and less production of chest physical therapy treatments. 21 1 ~Moreover, some hospl ta]s contract out to private firms for respiratory services. This arrangement may also alter the pattern of respirator y treatments performed. ZOThe smallest hospita] had more than 330 beds and the largest had 848 beds in 1979. ~lAgain, it shou]d be noted that without data on the severity of illness of the mix of patients treated in hospitals of different sizes, normative judgments concerning the appropriateness of the treatment are not possible.

PAGE 21

Table 2.Utilization of Respiratory Therapy by Hospital Bed-Size, 1979 a (per 100 admissions per month) Up to 150 150 to 250 250 to 450 >45 0 Total patients treated with respiratory therapy . . . Total respiratory therapy treatments . . . . . IPPB patients. . . . . . . . . . . IPPB treatments . . . . . . . . . Incentive spirometry patients . . . . . . . Chest physical therapy treatments. . . . . . beds beds beds beds All hospitals 18b 18b 52b 42 44 N= 2 N= 2 N= 3 N= 4 N = 11 720 842 710 760 723 N= 5 N= 5 N= 7 N= 6 N =23 13 12 6 6 6 N= 6 N= 6 N= 7 N= 8 N =27 105 105 111 25 60 N = 10 N= 7 N = 12 N= 8 N =37 15 30 9 10 12 N = 10 N= 5 N= 9 N= 5 N =29 43 27 54 107 66 N= 5 N= 6 N= 9 N= 5 N = 25 N = Number of responding hospitals b because of the small number of observations In these categories, these data should be used With Caution a Based on hospitals In the Washington DC SMSA In order to make observations concerning any Table 3 shows trends from 1976 to 1979 in the recent changes in the utilization of respiratory utilization by these five hospitals of four restherapy modalities, especially IPPB, we selected piratory treatment modalities: 1) IPPB, 2) ultraa sample of five teaching hospitals from the sonic nebulizer, 3) simple aerosol, and 4) incenuniverse of 43 hospitals in the Washington, tive spirometry. Of considerable interest is the D. C., SMSA that delivered respiratory therapy dramatic reduction in the number of IPPB treatservices in 1979. These five teaching hospitals are large, with an average bed-size of 626 beds, and have an occupancy rate of about 82 percent. Table 3.Trends in the Utilization of Four Respiratory Therapy Treatment Modalities, 1976 a 1976 b 1977 b IPPB treatment Total IPPB treatments . . . . . . . . . 121,772 111,990 IPPBs/ 100 admissions per month ., . . . . . . . 108 100 IPPBs/bed . . . . . . . . . . . . . 38.89 36.92 Ultrasonic nebulizer treatment Total ultrasonic treatments . . . . . . . . . 8,847 8,501.5 Ultrasonics/100 admissions per month e . . . . . . . 13 9 Ultrasonics/bede. . . . . . . . . . . 3.65 3.66 Simple aerosol treatment Total simple aerosol treatments . . . . . . . . . 32,337 47,715 Simple aerosols/100 admissions per month . . . . . . 29 43 Simple aerosols/bed, . . . . . . . . . . . 10.33 15.73 Incentive spirometry treatment Total incentive spirometry treatments . . . . . . . 8,543 f Spirometry treatments/100 admissions per month g . . . . . 18 Spirometry treatments/bed . . . . . . . . . . 8.48 Incentive spirometry patients . . . . . . . . incentivespirometry patients/100 admissions per month . . . . Incentive spirometry patients/bed . . . . . . . . a Based on data from the followtng hospltals in the Washington D c SMSA George Washington Unlversity Hospital, Holy Cross Hospital, Veterans Admlnlstratlon Hospital Fairfax Hospital and Washington Hospital Center 1976 1977 1978 1979 Average bed size 6262 6066 6066 6066 Average admissions/bed 358 3692 3692 3692 Occupancy rate 8274 8352 8352 8352 Census of hospital beds 2.539 2,498 2,498 2,498 We are assuming that the figures for 1978 and 1979 were the same as those for 1977 b Full year statistlc 1978 bc 1979 c 50,698 45 16.72 36,418 d 33d 12.o1 d 2,350.5 3 1.01 91,088 81 30.03 13,240 f 27 13.25 7,656 h 0.12 2.69 2,976 d 3d 1.29 d 131 ,066 d 117d 43.21 d 16,1 38 f 33 16.03 7,792 h 0.12 3.75 cWe are assuming the number of beds and admissions remains COn Skiflt a! 1977 levels d I g7g figures were estimated by doubllng the first 6 months statistics Ultrasonic figures are comp!led from four hospitals f~wo hospitals Supplled this Stat lstlc 9For IWO hospitals reporting splrornetry, admissions = 48,746 and bed s -1,007, and for three hosp(tals reporting splrometry admusslons = 63,259 and beds = 2,076 hThree hospitals supplled this Stat lS!lC

PAGE 22

. 14 l Background Paper #2: Case Studies of Medical Technologies ments per 100 admissions and per hospital bed over the 1976-79 period. During that period, the number of IPPB treatments per 100 admissions declined about 70 percent (from 108 IPPB treatments in 1976 to an estimated 33 treatments in 1979). The number of ultrasonic treatments per 100 admissions declined about 75 percent (from about 13 ultrasonic treatments in 1976 to 3 treatments in 1979). The number of simple aerosol treatments per 100 admissions in these hospitals increased from 1976 to 1979 over 300 percent (from 29 treatments to 117), and the number of incentive spirometry treatments per 100 admissions increased from 1977 to 1979 over 200 percent (from 18 treatments in 1977 to 33 treatments in 1979). 22 23 22 The per bed comparisons are quite similar. 23 Data demonstrating a similar dramatic decline in the frequency of use of IPPB in selected hospitals were presented at the Atlanta Conference on the Scientific Basis of Respiratory Therapy in November 1979. A survey from a 1 ,000-bed New York City Hospital revealed a rapid decline since 1973. The Massachusetts General Hospital witnessed marked decrease in use of IPPB since 1974. Similar results have been observed at four unidentified Midwest hospitals, Dr. Steven Ayers, professor and chairman of the Department of Medicine of St. Louis University, speaking on the magnitude of use and cost of in-house respiratory care, said that a national decline of approximately 70 percent had occurred in the use of IPPB. (It should be recalled that the Sugarloaf Conference on the Scientific Basis of Respiratory Therapy took place in 1974. ) ESTIMATES OF THE RELATIVE COSTS OF RESPIRATORY TREATMENT MODALITIES The significant decrease in the utilization of IPPB and ultrasonic treatments and the increase in utilization of simple aerosol and incentive spirometry treatments in five major teaching hospitals in the Washington, D. C., SMSA may represent important new trends in respiratory therapy. One important reason for these trends is that for some therapeutic indications these different treatment modalities may well be substitutes for one another. 24 In delivering a medication to a patient, a simple aerosol device has been found to be as effective as an IPPB machine (25). It seems quite likely that other substitutions among treatment modalities exist, but documentation is currently limited. Using data from our Washington, D. C., SMSA hospital survey, we estimated differences in the relative cost of producing the following respiratory treatment modalities: 1) IPPB, 2) ultrasonic nebulization, 3) simple aerosol. and 4) incentive spirometry. 25 It was assumed for ou r calculations that the effectiveness of these four treatment modalities is equivalent, It was also assumed that the amount of physician time reZqsee Burton, et a], (g) [or a discussion of some of these modalities. ZsThe re]atlve cost estim,]tes include resource costs that differ among treatment modalities, e.g., equipment and respiratory therapy personnel time. Thus, c,mts common to each treatment modality, such as overhead and the physicians time used in ordering the treatments, are not included. quired for each modality is equal, because the physicians role is to select the appropriate treatment modality. For each of the four modalities, the actual delivery of treatment to the patient is the responsibility of different types and levels of respiratory personnel. The delivery usually involves the time of a therapist and the use of the needed equipment 26 In order to estimate relative costs, we first examined the types of personnel involved and the amount of time required to deliver each of the treatment modalities. As shown in table 4, for three of the four modalities, about 70 percent of the responding hospitals in our Washington, D. C., SMSA survey reported that either a respiratory technician or therapist delivered the treatment. For incentive spirometry, nearly 5 0 percent of the hospitals use either a therapist or technician, and about 23 percent use a therapist or a nurse. These data suggest that some hospitals use these different types of personnel somewhat interchangeably. For our relative cost estimates, it was assumed that there are no significant differences in the respiratory therapy personnel used for the four treatment modalities under consideration, Table 5 shows the modal amount of personnel time necessary to deliver zbwe are assuming that the hosp] tal overhead allocated does not differ significantl y for ditferent equipment.

PAGE 23

Case Study #12. Assessing Selected Respiratory Therapy Modalities Trends and Relative Costs in the Washington, D C A Area l 15 four types of respiratory therapy treatments. 27 It is clear that IPPB treatments require the greatest amount of personnel time. For purposes of our cost estimates, delivery time for each modality was assumed to be at the higher end of the interval reported in table 5. The followup treatment time was assumed to be identical to the initial setup and treatment time. 28 Since respiratory personnel appear to be used somewhat interchangeably by a significant number of hospitals in our survey, an average wage paid of $12,000 per year was used for our calculations .29 Table 4.Personnel Used To Deliver Various Respiratory Therapy Treatments Frequency of Percentage of response respondent s IPPB treatment Technician or therapist . . 31 72.1 /o Therapist, . . . . . 5 11.6 Technician . . . . 4 9.3 Therapist or nurse . . . 3 7.0 Ultrasonic nebulizer administration of a drug Technician or therapist . . 29 69.0 Therapist. . . . . . 6 11.9 Technician . . . . . 5 11.9 Therapist or nurse . . . . 2 4.8 Simple aerosol generator administration of a drug Technician or therapist . . 29 69.0 Therapist. . . . . . 5 11.9 Technician ... . . . . 5 11,9 Therapist or nurse . . . . 2 4.8 Incentive spirometry treatment Technician or therapist . . 21 48.8 Chest physical therapist . . 1 2.3 Any nurse . . . . . 3 7.0 Therapist, ... . . . 4 9.3 Technician . . . . . 3 7.0 Therapist or nurse . . . 10 23.3 a~~ ~ n ho s pital s Irl the Washington, D C ~ SMSA bBecause of mlsslng observations, totals may not equal 100 Percent The modal time was used instead of the mean, because the data were not normal I y distributed. Z~In many Instances, fo]]owup treatment will require less time. Hence, the ct)st estimates of followup treatments may have an upma rd bias. 1Thi+ wage tlgure is reported b y the Bureau of Labor Statistics, lr]dustry Wage Sur-Lvy, Washington, D. C., SMSA, September 1978 (7). The cost of fringe benefits would add about 20 percent to these estimates. Obviously, as the mix of personnel changes or differs between hospitals, costs w1lI also change In a corresponding manner, Table 5.Modal Time Required by a Respiratory Therapist or Technician To Deliver Various Respiratory Therapy Treatments Treatment modality Modal time in minutes IPPB treatment . . . . . 20-25 Ultrasonic nebulization of a medication 15-20 Aerosol medication treatment delivered by a simple aerosol generator . 15 Instruction to patient for incentive spirometer . . . . 10-15 a Based o n hospitals In the Washington D c SMSA We combined the cost of personnel time with the cost of equipment to estimate the cost differentials between these four different treatment modalities. First, we examined the personnel and equipment costs for delivery of medication or improving inflation of the lungs with an IPPB machine. The various types of IPPB machines currently sell for about $600 and have an expected life of 15 years. However, to be liberal in our estimates, we depreciated the IPPB equipment costs in 7 years using a straight-line depreciation method. This produced a yearly cost of about $85 per year, or about $0.14 per treatment. 30 There is also a one-time charge of about $2.35 for disposable tubing to connect the patient to the machine. The machine is usually powered by compressed air or oxygen, for which we added a generous allowance of $1.00 per treatment. The personnel costs for IPPB are about $2.90 for 25 minutes of personnel time. The estimated cost for initial setup and treatment with IPPB, therefore, is about $6.40. 31 A followup treatment would cost $4.05, because it would include only the personnel, machine, and the electricity y costs. For the delivery of medication with an ultrasonic nebulizer, we estimate the following costs. A nebulizer which currently costs $580 is assumed to depreciate over the same time span as the IPPB machine. There also is a one-time charge for each of the following disposable We used 25 treatments per week, which we calculated from the survey data. Recall that this estimate is not the full cost of respiratory therapy, because overhead costs and the cost of physicians time are omitted Since the omitted costs are similar for the four treatment methods, they do not affect the differences i n costs,

PAGE 24

items: an ultrasonic cup, $2.00; tubing, $0.70; mask, $0.60; and electricity costs, $1.00. 32 Th e personnel costs for 20 minutes are about $200. This produces a total cost of about $6.30 for an initial setup and treatment. The followup treatment in most instances involves only the personnel, machine, and electricity costs, which amount to $3.14. Next, we estimate the personnel and equipment costs of delivering a medication by a simple aerosol generator. The equipment cost for simple aerosol is $3.50, and the cost of 15 minutes of personnel time is $1.50, making the total cost for the initial setup and treatment about $5.00. For each followup treatment that requires only personnel, 33 the cost would be only $1.50. The costs for incentive spirometry to improve lung inflation include the cost of the spirometer itself, $8.60, and the cost of personnel time needed to instruct and supervise the patient in the spirometers use. This instruction and supervision takes an average of 15 minutes, at a personnel cost of approximately $1.50. This produces an initial treatment cost of $10.10. The cost of a followup treatment is only $1.50 assuming that personnel time is still required but the same instrument is used. (Recall that these relative cost estimates, as well as the others presented, do not include the cost of the physicians time or overhead since these costs are common to all the treatment modalities. ) z The $1 cost of electricity is only a ver y rough estimate. ~JThls is th e case i f the aerosol generator is reused. The relative cost estimates shown in table 6 suggest that for initial treatment, incentive spirometry has the highest relative cost, and simple aerosol has the lowest. The relative costs of the IPPB machine and the ultrasonic nebuIizer fall between these. Comparing the calculated relative costs for initial treatment to hospital charges for initial treatment shows the largest difference between costs and charges for IPPB ; 34 the next largest difference is for the ultrasonic nebulizer. Respiratory therapy patients usually require multiple treatments, and the relative cost estimates in table 6 suggest that for a followup treatment, IPPB and the ultrasonic nebulizer have the highest relative costs. The largest difference between the relative cost estimates and hospital charges for a followup treatment is for the simple aerosol; the next largest difference is for the IPPB machine. For a followup treatment, hospital charges are the highest for the IPPB machine. It is interesting to view these findings in the light of recent trends in the utilization of different respiratory treatment modalities. As noted in the previous part of this case study, at five major teaching hospitals in the Washington, D. C., SMSA, the use of the IPPB machine and the ultrasonic nebulizer is declining, while the use of the incentive spirometer and the simThese costs do not include the cost of physicians time or hospital overhead costs. Table 6.Estimates of Relative Costs and Charges for Four Respiratory Therapy Treatment Modalities b Difference between costs costs Charges and charges Initial Followup Initial Followup Initial Followup Treatment modality treatment treatment treatment treatment treatment treatment IPPB . . . . . $6.4 0 $ 4.04 $10.90 $8.90 $4.50 $4.86 Ultrasonic nebulizer . . 6.44 3.14 10.70 6.60 4.26 3.60 Simple aerosol. . . 5.00 1.50 8.70 6.90 3.70 5.40 Incentive spirometry. . . 10.10 1.50 13.10 6.10 3.00 4.60 scO~t~ l~lde onlY wages paid t. nonpflyslclan personnel and equipment related costs and do not Include the cost of Phwclans time or hospital overhead Costs The latter are assumed to be equal for the four treatments considered bcharges are mean values reported from our survey of the hospitals m the Washwton. D C SMSA

PAGE 25

Case Study #12 Assessing Selected Respiratory Therapy Modalities Trends and Relative Costs in the Washington D. C Area l 17 ple aerosol generator is increasing. For purposes of illustration, assume that half of the 70percent decrease over the 1976-79 period in utilization of IPPB treatments per 100 hospital admissions that we found in these hospitals were replaced by utilization of simple aerosols or incentive spirometry. For hospitals in the Washington, D. C., SMSA, this change would produce an estimated cost savings of about CONCLUSIONS AND IMPLICATIONS Over the past two decades, there has been phenomenal growth in the United States in respiratory therapy departments offering a variety of treatment modalities aimed at improving lung dysfunction. These departments offer four major types of therapy: 1) oxygen therapy, 2) humidity and other aerosol therapy, 3) chest physiotherapy, and 4) mechanical aids to lung inflation (including IPPB). In many instances, the increased use of these services has occurred without much scientific evidence demonstrating that they bring about a measurable improvement in the patients physical condition. We have reviewed research findings on what is known about the efficacy and effectiveness of respiratory therapy modalities, emphasizing in our review IPPB treatments delivered for several accepted therapeutic indications. Oxygen therapy is the least controversial respiratory therapy, because easily definable indications and outcomes can be measured during the administration of supplemental oxygen. The values of aerosol therapy and chest physiotherapy have not yet been scientifically demonstrated, although specific uses have been shown to be beneficial. The lack of scientifically demonstrated effectiveness is not proof that these therapies are not effective; it only indicates that we currently do not know that they are effective. IPPB treatments have enjoyed widespread acceptance for several therapeutic indications. For all of these indications, the rationale underlying the use of IPPB is the assumption that an IPPB machine can deliver a larger breath to the pa$408,000 per year .35 To estimate other potential savings would require more detailed data on the substitution between different treatment modalities. Research on the substitutability of different respiratory treatment modalities should receive a high priority. In making this calculation, we assumed that there was one initial setup cost per nine followup treatments. tient with less work required of the patient. We have found that there exists very little scientific evidence to support the overall efficacy of IPPB. Many studies that have compared IPPB to technologically less sophisticated devices (e. g., simple aerosols or incentive spirometers) have concluded IPPB is not more effective than the simpler alternative. To deliver an aerosol medication to a patient, for example, IPPB and a simple aerosol generator are comparable. In the prevention of postoperative lung collapse, IPPB treatments are at best comparable to the use of an incentive spirometer. Our analysis of data we collected on the hospitals in the Washington, D. C., SMSA showed that the utilization of different respiratory therapy treatment modalities varied substantially by type and size of hospital. Private for-profit hospitals delivered more IPPB treatments and fewer incentive spirometry treatments per 100 patient admissions than other hospitals; private for-profit and nonprofit hospitals delivered over twice the number of chest physical therapy treatments per 100 patient admissions that Federal and non-Federal Government hospitals did. As hospital size (number of beds) increased, the number of respiratory therapy patients and IPPB patients per 100 admissions declined. However, before normative judgments on these utilization differences can be made, the differences need to be related to the each hospitals case mix and the severity of illness of the patient population treated in each hospital. Our subsample of five teaching hospitals showed dramatic changes in the use of certain

PAGE 26

respiratory therapy treatments during the 1976-79 period. The utilization of IPPB and ultrasonic treatment declined over 70 percent, while utilization of incentive spirometry and simple aerosol doubled. Although we did not explore all the reasons for this change, it does seem plausible that the 1974 Sugarloaf Conference on the Scientific Basis of Respiratory Therapy and editorials in medical journals had an impact on IPPB use in teaching hospitals. What is surprising is the vast amount of flexibility that respiratory therapy departments appear to have and the speed at which changes in treatment modalities can be accomplished. According to our relative cost estimates, changes away from the use of IPPB machines and ultrasonic nebulizers toward the use of incentive spirometers and simple aerosol generators appear to be a move in the direction of selecting the least costly treatment modalities. Our relative cost estimates also suggest that for a followup treatment, an incentive spirometer and a simple aerosol generator are substantially less costly than an IPPB machine or an ultrasonic nebulizer. The move toward utilization of less costly respiratory treatment modalities by the hospitals in our subsample appears to have occurred without Government regulation and without any planning. As an illustration of a possible cost savings, we estimated that the substitution of simple aerosols or incentive spirometry for half the decrease in IPPB could produce yearly cost savings of about $400,000 fo r the hospitals in the Washington, D. C., SMSA. The validity of this assumption and the possibility of other cost-effective substitutions between treatment modalities warrant further study. Performing a rigorous cost-effectiveness analysis of respiratory therapy would involve the use of a prospective random sample of patients using different respiratory therapy treatment modalities. Data on measurable health outcome parameters and costs of the different therapies would be required. The cost comparisons should include all hospital costs related to the treatment of the patient.

PAGE 27

APPENDIX: QUESTIONNAIRE USED IN WASHINGTON, D. C., SMSA RESPIRATORY THERAPY DEPARTMENT SURVEY Hospital Name Medical Director Technical Director Additional Information County 1. How many patients in toto were treated by your respiratory therapy department last month? 2. How many total treatments/interventions were administered by your department last month? 3. 4 5. 6 Are IPPB treatments administered in your hospital? *If not, what other types of therapy have replaced IPPB treatments? How many total IPPB treatments were administered last month? How many different patients received IPPB therapy last month? Is incentive spirometry available in your hospital? 7. How long has incentive spirometry been available at your hospital? 8. How many patients used incentive spirometry in the past month? 9. How many incentive spirometry treatments were administered last month? 10. What type(s) of incentive spirometer do you use? a. b.

PAGE 28

20 l Background Paper #.2: Case Studies of Medical Technologies 11. Who initiates the spirometry therapy? Who follows up in the treatment? For how many days is supervised therapy given? How many times a 12 0 Is a charge made day is supervised therapy given? for each supervised use of the incentive spirometer or just for the initial set-up? 13. What percent of treatments are administered by each of the (% should total 100%) Installations Ins. % Treatments a. IPPB machine b. Ultrasonic nebulizer c Simple aerosol generator d. Other 14. How many chest physical therapy treatments do following routes? Treat % you give pe r month? 15 What is the amount of time required for one of your respiratory technicians or therapists to perform each of the following interventions? a. An IPPB treatment b. Instruction to the patient about how to use an incentive spirometer c Ultrasonic nebulization of a medication d. Aerosol medication treatment delivered by a simple aerosol generator 16. What is the charge to the patient for the following? a IPPB installation b. IPPB treatment

PAGE 29

Case Study #12 Assessing Selected Respirator.v Therapy Modalities: Trends and Relative costs I n the Washington, D C Area l 21 c d e f g h. l. j k. Ultrasonic nebulization of a medication Aerosol medication treatment delivered by a simple aerosol generator 1P PB treatment with an aerosol of medication Simple aerosol medication installation Simple aerosol medication treatment Blow bottle installation Blow bottle treatment Incentive spirometry set-up Incentive spirometrv followup treatment or if patient is charged a flat fee per day, amount of that per day charge l 17 Who delivers each of the following types of therapeutic interventions? a. b. c* d. 18. In IPPB Incentive spirometry Ultrasonic nebulizer administration of a drug Simple aerosol generator administration of a drug what medical/surgical specialty is your medical director trained (e.g., pulmonary medicine, anesthesiology, thoracic surgery, etc.)? 19. How many total employees are there in your department? a. How many are registered therapists? b. How many are certified technicians? c How many are registry eligible graduates? d. How many are students? e. How many are on-the-job trained? f. How many are other? (Please specify.)

PAGE 30

. 20 How many a. Full b. Part 21. How many a. IPPB of your employees time time of the f 01 lowing machine are pieces of equipment do you own? b. Ultrasonic nebulizers c Volume-cycled ventilators REFERENCES 1, 2. 3. 4. 5. 6. 7. 8. 9. 10. American Thoracic Society Respiratory Care Committee Position on IPPB, Am. Thor. Soc. News 5, summer 1978. Baker, J. P., Magnitude of Usage of Intermittent Positive Pressure Breathing, in Proceedings of the Conference on the Scientific Basis of Respiratory Therapy, Amer. Rev. Resp. Dis. 110:170, 1974. Baxter, W. D., and Levine, R. E., An Evaluation of IPPB in the Prevention of Post-Operative Pulmonary Complications, Arch, Surg. 98:795, 1969. Becker, A,, et al., The Treatment of Postoperative Pulmonary Atelectasis With IPPB, Surg. Gyn. 111:517, 1960. Birnbaum, M. L., et al., Effects of IPPB on Emphysematous Patients, Am. J. Med. 41 :552 1966. Bunch, D. Spotlighting the Profession: The Uniform Manpower Survey of the American Association of Respiratory Therapists (Dallas, Tex.: Americar Association of Respiratory Therapists, 1976). Bureau of Labor Statistics, lndustry Wage Surile y (Washington, D. C.: BLS, September 1978). Burton, G., et al. (eds. ), Respiratory Care: A Guide to Clinical Practice (Philadelphia, Pa.: J. B. Lippincott, 1977). Conference on the Scientific Basis of Respiratory Therapy: Physical Therapy, An-z. Rev, Resp, Dis. 110(6) (pt. 2), 1974. Egan, D. F., Fundamentals of Respiratory Therapy (St. Louis, Me.: C. V. Mosby, 1977). 11. 12. 13. 14. 15. 16. 17. 18. 19. Emmanuel, G. E., et al., The Effect of IPPB and Voluntary Hyperventilation Upon the Distribution of Ventilation and Pulmonary Blood Flow to the Lung in Chronic Obstructive Lung Disease, J. Clin. lnv, 45:1221, 1966. Fowler, W. S., et al., Treatment of Pulmonary Emphysema With Aerosol Bronchodilator Drugs and Intermittent Positive Pressure Breathing, Proc. Staff Meet. Mayo. Clin, 28:743, 1953, Froeb, H. F., Induction of Alveolar Hyperventilation: A Comparative Study of Nebulized Bronchodilators by Deep Breathing and Intermittent Positive Pressure, Dis. Chest 38:483, 1960. Gold, M. 1., The Present Status of IPPB Therapy, Chest 67(4):469, 1975. Goldberg, I., and Cherniak, R. M., The Effect of Nebulized Bronchodilator Delivered With and Without IPPB on Ventilator Function in Chronic Obstructive Emphysema, Amer. Rez). Resp. Dis. 91:13, 1965. The Hospital Record Study (Ambler, Pa. : CPHA and IMS America Ltd., 1978). Hudson, L. D., Is IPPB Effective? A Controversy in Respiratory Therapy, Prim. Care, 5(3): 529, 1978. Iverson, L. I., et al., A Comparative Study of IPPB, the Incentive Spirometer, and Blow Bottles: The Prevention of Atelectasis Following Cardiac Surgery, Am. Thorac, Surg. 25(3) : 197, 1978. Jones, R. H., et al., The Effects of IPPB in

PAGE 31

20. 21. 22. 23. 24. 25. 26. 27. 28. Simulated Pulmonary Obstruction, Am. Rev. Resp. Dis. 82:164, 1960. Kamat, S. R., et al., The Effects of IPPB With Compressed Air in Patients With Severe Chronic Nonspecific Obstructive Pulmonary Disease, Amer. Rev. Resp. Dis. 86:360, 1962. Keighley, J. F. H., Response to Sympathomimetic Aerosols of Differing Particle Size in Subjects With Chronic Bronchitis, Amer. Rev. Dis. 98:879, 1968. Krumholz, R. A., and Hayward, D. R., Respiratory Therapy Utilization in a General Hospital, Inhal. Ther. 13(4):1968. Leslie, A., et al., Intermittent Positive Pressure Breathing: Appraisal of Use in Bronchodilator Therapy of Pulmonary Emphysema, }. A.M.A. 160:1125, 1956. Murray, J. F., The Ketchup Bottle Method, N. Eng. ]. Med. 300(20): 1155, 1979. Noehren, T. H., IPPB TherapyWhere Do We Go From Here? Chest 67(4):471, 1975. Noehren, T. H., and Barnett, T. B., Bronchodilator Aerosol, Comparison of Administration Methods, ]. A.M.A. 223(8):884, 1973. Noehren, T. H., and Klauber, M. R., Controversy Over IPPB (editorial), Ches t 73(6):782, 1978. Office of Technology Assessment, U.S. Congress, Assessing the Efficacy and Safety of Medical Technologies, GPO stock No. 052-003 00593-O (Washington, D. C.: U.S. Government Printing Office, September 1978). 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. Proceedings of the Conference on the Scientific Basis of Respiratory Therapy, Final Report on IPPB, Am. Rev. Resp, Dis. (pt. 2), 110(6):13, 1974. Racz, I., et al., Comparative Efficacy of Two Methods of Bronchodilator Administration, in Transactions 28th VA-Armed Forces Pulmonary Disease Research Conference, 1969. Russell, L., Technology in Hospitals: Medical Advances and~ Their Diffusion (Washington D. C.: The Brookings Institution, 1979). Sands, J. H., et al., A Controlled Study Using Routine IPPB in the Post-Surgical Patient, Dis. Chest 40:128, 1961. Shim, C., et al., The Effect of Inhalation Therapy on Ventilator Function and Expectoration, Chest 73(6):798, 1978. Smelzer, T. H., and Barnett, T. B., Bronchodilator Aerosol, Comparison of Administration Method, l. A.M.A. 223(8):884, 1973. Sukumalchantra, Y., et al., The Effect of IPPB in Acute Respiratory Failure, Am. Rev. Resp. Dis. 92:885, 1965. Wu, N., et al., IPPB in Patients With Chronic Bronchopulmonary Disease, Amer. Rev. Tuberc. Pul. Dis. 71:693, 1955. Yorzyk, W. A., et al., Organization of Hospital Departments of Inhalation Therapy, J, A.M.A. 203(8):552, 1968. Ziment, I., Why Are They Saying Bad Things About IPPB? Resp. Car< 18(6): 677, 1973. U S GOVERNMENT PRINTING OFFICE 198: 341-844 II 11


xml version 1.0 encoding UTF-8
REPORT xmlns http:www.fcla.edudlsmddaitss xmlns:xsi http:www.w3.org2001XMLSchema-instance xsi:schemaLocation http:www.fcla.edudlsmddaitssdaitssReport.xsd
INGEST IEID ER8L9M082_XQ2DZO INGEST_TIME 2017-05-18T17:33:52Z PACKAGE AA00055059_00004
AGREEMENT_INFO ACCOUNT UF PROJECT UFDC
FILES