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Reducing Length of Stay for Patients Hospitalized With Exacerbation of COPD by Using a Practice Guideline
Reducing Length of Stay for Patients Hospitalized With Exacerbation of COPD by Using a Practice Guideline* Gary K. Kong, MD, MPH; Michael]. Belman, MD; and Scott Weingarten, MD, MPH
Clinical practice guidelines have been promoted as an effective way of reducing costs while maintaining quality care. Objective: To study a practice guideline to shorten length of stay for patients hospitalized with exacerbation of COPD. Methods: We retrospectively studied a practice guideline to identify patients who were at low risk of complications from their exacerbation of COPD and hence potentially suitable for early hospital discharge. We then prospectively studied the practice guideline using an alternate month intervention and control time series over a period of 12 months. Results: The practice guideline was retrospectively studied in 250 consecutive patients hospitalized with exacerbation of COPD. Of the 250 patients, 237 patients (94.8%) were classified as low risk after 72 h of hospitalization and were potentially suitable for discharge. In the prospective study, few patients (24 of 124 or 19%) were identified for implementation of the guideline. However, in those patients who were identified, length of stay was not statistically different. The data also showed that length of stay for both intervention and control groups had shortened over this time. Conclusion: Certain practice guidelines may appear efficacious in studies but may actually lack effectiveness when applied in clinical settings and may even increase costs. We demonstrated the importance of prospectively evaluating clinical practice guidelines before recommending them for widespread implementation. (CHEST 1997; 111:89-94) Key words: chronic obstructive pulmonary disease; length of stay; practice guideline
c
OPD is one of the most common causes of hospitalization, disability, and death. The estimated number of individuals with chronic bronchitis and emphysema in the United States is ll million and 2 million patients, respectively.l- 5 COPD also results in significant economic costs and was responsible for 2 million hospitalizations and $4.3 billion in direct costs in 1985_1-3.5 Morbidity caused by COPD results in an additional $2.9 billion in indirect costs. 3 There are few available data on the effectiveness and safety of clinical practice guidelines that identify COPD patients at low risk for complications and hence suitable for early discharge from the hospital. This was reiterated by the American Thoracic Society which wrote in 1995 in the standards of care for *From the Department of Health Services Research and the Division of Pulmonary and Critical Care Medicine, Cedars-Sinai Medical Center, UCLA School of Medicine, Los Angeles. Manuscript received April 4, 1996; revision accepted September 10. Reprint requests: Dr. Kong, Cedars-Sinai Medical Center, Division of Pulmonary and Critical Care Medicine, Room 6732, 8700 Beverly Blvd., Los Angeles, CA 90048.
patients with COPD that there was "insufficient data to establish the duration of hospitalization in individual patients to achieve maximal benefit," although they did list some criteria that they admitted as being supported by limited data and consensus. 6 The guideline, however, lacks the specificity to improve the efficiency or quality of care beyond current medical practice or to alter physician practice patterns. Guidelines should be explicit and substantive, and preferably based on outcomes data, to affect physician practice significantly and favorably. 7 •8 A recent study by Mushlin and colleagues 9 demonstrated that the necessary lengths of stay for patients with COPD may be significantly less than actual lengths of stay. 9 The study de monstrated that 90% of patients with COPD were free of complications or the need for monitoring after 6 hospital days, although these patients remained hospitalized for an average of 8.7 days. However, this study was limited by a relatively small sample size (n=83). Therefore, we retrospectively studied a practice guideline that identified "low-risk" patients admitted CHEST I 111 I 1 I JANUARY, 1997
89
to the hospital with exacerbation of COPD that could potentially safely reduce their length of hospital stay. The retrospective study showed that the guideline had potential for saving many hospital days by early discharge of low-risk patients and did not appear to compromise quality of care. This guideline was then implemented prospectively on low-risk patients admitted to the hospital to assess its impact on length of stay and quality of care.
MATERIALS AND METHODS Methods
The study was a retrospective analysis of patients hospitalized with exacerbation of COPD. Patients were classified at low risk for development of complications accordin g to the guideline. We investigated the potential effects of the guideline in recommending a 3-day length of hospital stay and on quality of care. We then went on to determine if the practice guideline studied would have an impact on shortening length of stay while maintaining or improving quality of care. Description of the Institution
The study was performed at Cedars-Sinai Medical Center, a large teaching community hospital that serves west Los Angeles. Most hospitalized patients are cared for by physicians in private practice. Description of Patients
We analyzed patients over th e age of 45 years who were consecutively hospitalized with worsened dyspnea di agnosed as exacerbation of COPD over the period of January 1992 to March 1993. We chose charts of patients from the hospital discharge database and selected according to the Ninth Revision of the International Classification of Diseases codes. 10 These codes are listed in Appendix l. Sixty percent of all the reviewed charts met the inclusionary criteria and were ente red into th e study. Patients were excluded from the study if th ey had pulmonary diagnoses at th e time of hospital admission other than or in addition to COPD---eg, pulmona1y embolism, pneumonia, bronchiectasis. Patients were also excluded if the primary reason for hospital admission was not exacerbation of COPD (eg, urosepsis, abdominal pain), if they had severe congestive heart fai lure ( New York Heart Association class IV), if they had chest pain consistent \vith myocardia\ si chemia, or if they were intubated and ventilated on the day of admission. Practice Guideline
Afte r a r veiew of the medical lite rature, 9 • 11 the practice guideline was formalized by consensus within a study group comprised of two internists and a pulmonologist. The guideline stated that patients who had none of th e following complications at 72 h after hospitalization were placed in a low-risk category and were potentially suitable for early discharge. These complications are listed in Appendix 2. Furthermore, patients who developed major complications (Appendix 3)12 during the first 72 h of hospitalization were unsuitable for conside ration for early discharge and hence excluded from th e study.
90
Definition of Need for Continued Hospitali;:;ation
The occurrence of a significant medical complication, as described above, after the third hospital day served as a marker for the need for continued hospitalization. After a complication was identified, the need for continued hospitalization was determined by hvo physicians' implicit judgment. The physicians judged that continued hospitalizati on was necessary when a patient developed a complication th at may have benefited from continued hospitalization. Continued hospitalization was considered potentially unnecessary if th e patient had an uncomplicated hospital course. This method of quality of care review had been used in several previous practice guideline validation studies.l3. 14 Complications Explicit RetJiew: Complications were abstracted from th e medical record by the research fellow. Patients who were determined to be at low risk on th e fourth hospital day and who then suffered the above-defined complications after that day were considered to be potentially misclassified by th e guideline. The potential misclassifications were th en submitted to the physicians for implicit review. Implicit Revieu;: All complications occurring in low-risk pati ents on and after the fourth hospital day we re implicitly and independently reviewed b y hvo physicians (a board-certi fied inte rnist and a board-certified pulmonologist) who were not blinded t o th e patient's risk status. The physicians rated whethe r discharge horne would have worsened quality of care, that is, patient outcome may have been compromised h ad th e patient been home at the time of the development of the compLication. These outcomes included potential need for e mergency department intervention or rehospitalization with the development of the complication \vi thin 7 days of hospital discharge. In cases of disagreement, th e judgment of the physician who felt that the guideline wou ld have worsened quality of care was used as the "gold standard," hence using the most conservative definition possible. Calculation of Lengths of Stay
The expected benefit in bed utilization afford ed b y the guideline was the projected reduction in hospital bed-days. For each low-risk patient, the hypothetical number of hospital bed-days saved was estimated had the guideline been used to prescribe patient care. The number of bed-days saved was defined as the actual number of days in the hospital less the number of days in hospital recommended by the practice guideline. Prospective Guideline Intervention
After formali zation of the guideline, the case manager d edicated to the respiratory ward was briefed on the inclusion and exclusion criteri a of the practi ce guideline. The study was then presented and approved by the institutional review board for implementation. A letter was sent out to all internal medicine and pulmonary attending staff outlining the clinical practice guideline and its aims prior to the start of th e study. The study was then implemented in an alternate month intervention and control time series over a period of 12 months. Intervention M ethod
Low-risk pati ents admitted to th e respiratory floor with exacerbation of COPD were identified by the case manager and admitted into the study. The intervention was as follows. Clinical Investigations
(1) At 48 h postadmission, a letter was placed in the file informing the attending physician that his or her patient was low risk and was suitable for discharge after 72 h of hospitalization , if no complications developed in the preceding 24 h. (2) On revisit, if there were no plans to discharge the patient at the appropriate time, the physician would be contacted by the case manager and reasons elicited for maintaining in-patient care. The case manager would be supp01ted by a physician if necessary in cases where there was no apparent good reason for keeping a patient in hospital. (3) After hospital discharge, the patients would be interviewed by telephone and sent a Medical Outcomes Study SF-36 questionnaire between 1 and 3 months postdischarge, and any mortality or morbidity data would be obtained from the attending physician and chart review.
100
98 96
/o
0
94 92 90 88
Control Method
Low-risk patients admitted during the control months were identified by the case manager and recorded. After hospital discharge, the control low-risk patients would be followed up as outlined in step 3 above. The list of all patients admitted to the target ward was obtained and the charts of all the patients who had the appropriate International Classification of Diseases (ninth revision) discharge diagnoses were reviewed b y the investigator (G.K.K. ) who was blinded to the risk status of the patients as noted by the case manager. Statistical analysis was performed using a software package (True-Epistat).l 5 Nonpaired two-sided t tests were performed with p< O.OS used as the el vel of statistical significance. RESULTS
Retrospective Analysis Demographics: A total of 250 patients were included in the study. Medical records were available for abstraction on 97.8% of eligible patients. The average age of the study patients was 71.5 years (SD, 11.6). Women accounted for 68% of the patients. The mean hospital length of stay was 6.5 days (SD, 4.8). The outcomes of the patients were as follows : 94% discharged to home; 4.4% transferred to another facility; and 1.6% deaths. The proportion of patients classified as low risk according to th e guideline during each hospital day is represented in Figure l. Projected Effects of the Practice Guideline on Bed Utilization: A total of 94.8% of the patients would have been classified as low risk according to the guideline by the fourth day of hospitalization and hence suitable for consideration for early discharge. The estimated lengths of stay using the guideline to discharge low-risk patients after 3 hospital days was 3.2 days. As the average length of stay for these patients was actually 6.5 days (SD, 4.8), the number of bed-days saved p er patient had the guideline been used would have been 3.3 days. On an annual basis, the number of bed-days saved would have been 627 days on a projected annual number of 190 low-risk patients.
86
2
4
6
8
10
12
Days from admission (1 being day of admission) FIGURE l. Percentage of patients who were found to be a t low risk from the day of hospital admission and onwards.
Explicit and Implicit Judgment of Quality of Care: The percentage of the low-risk patients who suffered any of the defined complications after 72 h of hospitalization was 1.9% (four patients) with a 95% confidence interval of 0.3 to 3.6%. These patients' charts were then independently reviewed by an internist and a pulmonologist and it was judged by one that only three (1.4%) would have suffered worsened quality of care if the patient had been discharged according to the guideline, while the other physician agreed with the explicit judgment that all four patients would have worsened quality of care had they been discharged according to the guideline. This would translate to a hospital readmission rate of only 1.9%. The accuracy of the guideline when used for discharging low-risk patients after 3 days of hospitalization was 98.1 %. The 95% confidence interval was 96.4 to 99.7%. Prospective Study One hundred twenty-four COPD patients were admitted to the respiratory ward during the study period (Table 1). Only 24 patients (19%) were correctly identified as low-risk patients and entered into the study-these were the true-positives. Thirty patients (24%) were low-risk patients who were not identified for inclusion into the study-these were the false-negatives . Sixty-two patients (50%) were not included into the study because the written diagnoses at the time of case manager review did not mention COPD exacerbation, but the discharge diagnosis was one of exacerbation of obstructive airways disease-the true-negatives. Fifty-six perCHEST I 111 I 1 I JANUARY, 1997
91
Table !-Effectiveness of Case Management in Identifying Patients With COPD Exacerbation Who Were Considered to be at Low Risk*
Patient Truly at Low Risk According to Guideline Yes No
Case Manager Judged the Patient to be at Low Risk According to the Guideline* Yes , %
No,%
19 (n =24) 2 (n=3)
24 (n=30) 50 (n=62)
*Total n =124; five of th e charts (5%) were unavailable for review.
cent of these "true-negative" patients (35 patients) should have been included as low-risk patients, but they were excluded because diagnoses other than COPD exacerbation were placed in the chart during the first 3 days of hospitalization. Three patients (2%) were incorrectly identified as low-risk patients-the "false-positives." Overall, 65 of these 124 admissions (52% ) were low-risk patients who were not identified for inclusion into the study. The month-by-month length of stay for the lowrisk patients (the true-positives and the false-negatives ) are presented in Figure 2. The mean length of stay during all control months was 4.3 days. The mean length of stay during all intervention months was 3.7 days (p=O.ll6). The mean length of stay for all patients was 4.0 days. The mean length of stay for patients correctly identified by the case manager and in whom there was active intervention was 3 days (n=l4). There was no statistically significant difference in the results of the outcomes between the control and intervention groups (Table 2).
6 en
in'
Cl .~
--
5 4
>.
ctl
en
3
0
.I:
0>
c
2
Q) _J
1
Control versus Intervention Months FIGURE 2. Comparison of lengths of stay in control (white bars ) and intervention (dark bars ) months. No statistical differe nce (p =O. ll6).
92
Table 2-0utcomes of Patients Included in the Study* Variable
Control
Intetvention p Value
66.6±12.4 70.7::+::10.6 Age, yr Percentage female 45 59 3.7 4.3 Mean LOS, 1 d 0 0 Mortality 0 Transfer to highe r-level care: 0 Survival 1 mo postdischarge 11/11 = 100% 16/16=100% 11/11 = 100% 16/16= 100% Discharge to home Quality of life domains 35::+::35 42::+::33 Physical fun ction 17::'::41 Physical role 11 ±33 55::+::28 77::+::33 Bodily pain 60::+::27 General health 52::+::19 49::'::25 41±20 Vitality/energy 71::+:: 37 57::+::39 Social function 50::+::54 59::+::49 Emotional role 66::'::17 66::+::18 Mental health
0.27 0.42
0.70 0.78 0.19 0.51 0.50 0.48 0.74 0.97
*Total number=27; control, n =ll; intetve ntion , n=16. LOS = length of stay.
1
DISCUSSION
Patients hospitalized with exacerbation of COPD are commonly treated in the short-term care setting for approximately 6 to 8 days, although there is little evidence to suggest that this length of stay is necessary for all patients. 9 The retrospective study demonstrates that when patients are classified as low risk according to our guideline, the hospital length of stay could potentially be shortened to 3.2 days, with probably little effect on quality of care. As a consequence of this shortening of length of hospital stay, this guideline may reduce hospital costs. During the first 3 days of hospitalization, an increasing amount of data becomes available to the physician as to the progress of the patients-whether their conditions are improving or deteriorating. This guideline gives the physician objective criteria with which to identify patients who are at low risk for developing further complications related to their illness, and allows the physician to decide on the suitability of early discharge for his or her patient, without compromising quality of care. Mushlin et al 9 identified some factors that suggested which patients were less likely or more likely to require prolonged inpatient management. Other authors have identified factors that affect the longterm prognosis of patients with COPD, but none of these studies have been translated into a practice guideline that can be used to safely discharge patients who are at low risk for complications. 16-23 This particular guideline identifies a subset of low-risk COPD patients who can safely be discharged after 3 days of treatment in hospital. Many guidelines are developed using expert opinClinical Investigations
ion and literature review without evaluation of their impact on outcomes such as quality of care and health-care costs. 24 The development of a practice guideline also does not guarantee that it will be accepted and used by physicians in clinical practice. The testing of a guideline in a retrospective study provides some evidence for its safety and effectiveness (as was done in this study), and may facilitate its acceptance by practicing physicians. 25 However, as with the introduction of a n ew drug into clinical practice, the guideline needs to be validated in a prospective clinical trial before it can be recommended for widespread implementation. This guideline was therefore studied in a prospective controlled trial using an alternate month intervention/control time series. Based on the retrospective data, we projected a savings of over 3.2 bed days for low-risk patients admitted to the hospital with exacerbation of COPD. Several problems prevented us from reaching our target, although when implemented, the guideline did result in shorter stays without detracting from the patient's health status or satisfaction with care. The problems were as follows: (1) There was a failure to capture all patients on admission because of inaccuracy of written diagnosis. Patients whose charts did not expressly contain the word COPD exacerbation (35 patients) were excluded, and many who were labeled on admission as "asthma exacerbation," "bronchospasm," "exacerbation of asthmatic bronchitis," "rule-out pneumonia," "rule-out CHF" turned out to be low-risk patients with COPD exacerbation on chart review. These patients accounted for the majority of the patients excluded from the study. (2) There was a failure to capture patients even when all inclusion criteria were identified. Thirty patients (24%) who satisfied all criteria were not identified by the case manager. (3) There is a secular trend in southern California that has resulted in shortening of length of stays for COPD exacerbation even without intervention of the case manager and the use of the guideline. The intervention of the case manager in those cases that were correctly identified did result in a small decrease in length of stay. However, this difference was so small as to make the cost-benefit of the guideline minimal. Despite the shorter length of stay for all patients, we showed that less hospital days did not adversely affect clinical outcome. Potential Solutions
The inclusion criteria for the low-risk patients should be broadened to include all patients over the age of 45 years who have the various diagnoses in the chart synonymous with exacerbation of chronic air-
flow obstruction (eg, asthma exacerbation, asthmatic bronchitis, bronchospasm, who had been excluded in the prospective study), and not to exclude the "ruleouts" that may turn out to be exacerbation of airflow obstruction later on in the course of the hospitalization. Closer interaction between the physicians and case managers may improve the number of low-risk patients identified by the case manager, although this may increase indirect costs associated with guideline implementation in terms of physician and case manager labor costs. In conclusion, this study emphasizes the importance of prospective evaluation of guidelines before implementation. Failure to do so could result in inadequate guidelines that have no impact on achieving the desired outcome. ACKNOWLEDGMENTS: We would like to thank Patricia Hobson, RN , Susan Edinger, RN, and Mary Reidinger, RN , for assistance in the collection of prospective data and with the statistical analysis.
APPENDIX
1
International Classification of Diseases COPD and Allied Conditions 490-Bronchitis, not specified as acute or chronic (3%) 491-Chronic bronchitis (28%) 491.0-Simple chronic bronchitis 491.1-Mucopurulent chronic bronchitis 491.2-0bstructive chronic bronchitis- with and without exacerbation 492-Emphysema (10%) 493-Asthma 493.2-Chronic obstructive asthma (16%) 493.9-Asthma, unspecified (18%) sewhere classified (25%) 496-Chronic airways obstruction, not el (The number in parentheses represents the percentage of charts with each code.) APPENDIX 2
Minor Complications at 72 Hours of Hospitalization l. Dehydrati on Serum sodium level >155 mmol and/or a urea/creatinine ratio of > 20. 2. Hypotension Systolic BP >90 mm Hg or a >40 mm Hg reduction of BP from baseline. 3. Respiratmy acidosis An arteri al blood pH <7.30. 4. Hypoxemia on room air An arterial blood Po 2 <55 mm Hg or pulse oximetry saturation <88%. This rule applied unless the pati ent was known to be chronically hypoxic from history, that is the patient had a Po 2 <55 mm Hg under normal circumstances. 5. Hypercapnia An arterial blood Pc o 2 >45 mm Hg. This rule applied unless the patient was known to be chronically hypercapnic from history, that is the patient had a Pco 2 > 45 rnm Hg under normal circumstances. CHEST / 111 / 1 I JANUARY, 1997
93
6. Fever A temperature >38.3°C. 7. Development of a new infiltrate on the chest radiograph. 8. Inability to take food, fluids, or oral medications. 9. Development of new atrial or supraventricular tachyarrhythmias. 10. Poor functional status of the patient. This information was obtained from daily nursing assessment of patient's ability to perform activities of daily living, and nursing (and medical, when available) assessment of higher mental function.
APPENDIX
3
Mrqor Complications at 72 Hours of Hospitalization Pneumothorax. Ventricular fibrillation or ventricular tachycardia. Need for intubation and mechanical ventilation. New onset C!\S event, ie, cerebrovascular accident GI hemorrhage New-onset chest pain consistent with the diagnosis of myocardial ischemia. 7. Proximal deep venous thrombosis. 8. Pulmonary embolism. 9. Onset of acute renal failure-increasing BUN and creatinine that was not secondary to dehydration or obstruction. 10. Septic shock. Defined as sepsis (Ame rican College of Chest Physicians/Society of Critical Care Medicine Consensus Conference Definition ) with hypotension-a systolic BP <90 mm Hg or a reduction >40 mm Hg from baseline BP in the absence of other causes for hypotension despite adequate fluid resuscitation. 12 11. Cardiorespiratory arrest necessitating res uscitation. 12. Death.
l. 2. 3. 4. 5. 6.
REFERENCES l National Center for Health Statistics. Ten-year review and 5-year plan (vol 3); NIH publication No. 84-2358. Bethesda, Md: National Heart, Lung and Blood Institute, 1982 2 US Government Task Force. Epidemiology of respirat01y diseases: task force report on state of knowledge, problems and needs. US Department of Health, Education, and Welfare publication NIH 81-20193. Bethesda, Md: National Institutes of Health, 1980 3 Centers for Disease Control. Deaths due to chronic obstructive pulmonary disease and allied conditions. MMWR 1986; 35:507-10 4 Higgins MW, Keller JB. Trends in COPD morbidity and mortality in Tecumseh, Michigan. Am Rev Respir Dis 1989; l40:S42-S48 5 Murata GH, Gorby MS, Chick TW, et al. Use of e mergency medical services by patients with decompensated obstructive lung disease. Ann Emerg Med 1989; 18:501-06 6 American Thoracic Society, Medical Section of the Ametican Lung Association. Standards for the diagnosis and care of patients with chronic obstructive pulmonary disease (COPD). Am J Respir Crit Care Med 1995; l52:S78-l2l
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7 Lomas J, Anderson GM, Dominick-Pierre K, et al. Do practice guidelines guide practice?: the effect of a consensus statement on the practice of physicians. N Eng! J Med 1989; 321:1306-11 8 \Veingarten SR. The development, implementation, and evaluation of practice guidelines: a case example. Proceedings of the 41st Annual Group Health Institute. New York: 1991; 757-67 9 Mushlin AI, Black ER, Connolly CA, et al. The necessary length of hospital stay for chronic obstructive pulmonary disease. JAMA 1991; 266:80-3 10 International Classification of Diseases, 9th revision, clinical modifications. 4th ed. Salt Lake City: Med-Index Publications, Utah. 1993 ll Weingarten SR, Reidinger MS, Varis G, et al. Identification of low- risk patients hospitalized with pneumonia: implications for early conversion to oral antimicrobial therapy. Chest 1994; 105:1109-15 12 American College of Chest Physicians-Society of Critical Care Medicine Consensus Conference. Standardizing terminology in sepsis and multi-organ failure: definitions of sepsis. Northbrook, Ill, August 16-18, 1991 13 Donabedian A. Explorations in quality assessment and monitoring. (vol 2). Ann Arbor, Mich: Health Administration Press, 1982; 19-21 14 Weingarten S, Ermann B, Bolus H, et al. Early "step-down" transfer of low-risk patients with chest pain: a controlled interventional trial. Ann Intern Med 1990; 113:283-89 15 Gustafson TL. True epistat. H.ichardson, Tex: Epistat Services, 1992 16 Burrows B, Bloom }\\1, Tarver GA. The course and prognosis of different forms of chronic airways obstruction in a sample from the general population. N Eng! J Med 1987; 317: 1309-14 17 Anthonisen NR, Wtight EC, Hodgkin JE. Prognosis in chronic obstructive pulmona1y disease. Am Hev H.espir Dis 1986; 133:14-20 18 Ashutosh K, Dunsky M. Noninvasive tests for responsiveness of pulmonary hypertension to oxygen: prediction of survival in patients with chronic obstructive pulmonary disease and cor pulmonale. Chest 1987; 92:393-99 19 Boushy SF, Thompson HK, North LB. Prognosis in chronic obstructive pulmona1y disease. Am Rev H.espir Dis 1973; 108:1373-82 20 Johnston HN , McN eil HS, Smith DH. Chronic bronchitismeasurements and observations over 10 years. Thorax 1976; 31:25-9 21 Kanner RE, Henzetti AD, Stanish WM. Predictors of survival in patients with chronic airflow limitation. Am J M ed 1983; 74:249-55 22 Kawakami Y, Kishi F, Dohsaka K. Heversibility of chronic obstructive pulmonary disease. Chest 1988; 93:49-53 23 Kok-Jensen A, Sorenson E, Damsgaard T. Prognosis in severe chronic obstructive pulmonary disease. Scand J H.espir Dis 1974; 55:120-28 24 Audet AM , Greenfield S, Field M. Medical practice guidelines: current activities and future directions. Ann Intern Med 1990; 113:709-14 25 Selker HP. Criteria for adoption in practice of medical practice guidelines. Am J Cardiol 1993; 71:339-41
Clinical Investigations
Clinical practice guidelines have been promoted as an effective way of reducing costs while maintaining quality care. Objective: To study a practice guideline to shorten length of stay for patients hospitalized with exacerbation of COPD. Methods: We retrospectively studied a practice guideline to identify patients who were at low risk of complications from their exacerbation of COPD and hence potentially suitable for early hospital discharge. We then prospectively studied the practice guideline using an alternate month intervention and control time series over a period of 12 months. Results: The practice guideline was retrospectively studied in 250 consecutive patients hospitalized with exacerbation of COPD. Of the 250 patients, 237 patients (94.8%) were classified as low risk after 72 h of hospitalization and were potentially suitable for discharge. In the prospective study, few patients (24 of 124 or 19%) were identified for implementation of the guideline. However, in those patients who were identified, length of stay was not statistically different. The data also showed that length of stay for both intervention and control groups had shortened over this time. Conclusion: Certain practice guidelines may appear efficacious in studies but may actually lack effectiveness when applied in clinical settings and may even increase costs. We demonstrated the importance of prospectively evaluating clinical practice guidelines before recommending them for widespread implementation. (CHEST 1997; 111:89-94) Key words: chronic obstructive pulmonary disease; length of stay; practice guideline
c
OPD is one of the most common causes of hospitalization, disability, and death. The estimated number of individuals with chronic bronchitis and emphysema in the United States is ll million and 2 million patients, respectively.l- 5 COPD also results in significant economic costs and was responsible for 2 million hospitalizations and $4.3 billion in direct costs in 1985_1-3.5 Morbidity caused by COPD results in an additional $2.9 billion in indirect costs. 3 There are few available data on the effectiveness and safety of clinical practice guidelines that identify COPD patients at low risk for complications and hence suitable for early discharge from the hospital. This was reiterated by the American Thoracic Society which wrote in 1995 in the standards of care for *From the Department of Health Services Research and the Division of Pulmonary and Critical Care Medicine, Cedars-Sinai Medical Center, UCLA School of Medicine, Los Angeles. Manuscript received April 4, 1996; revision accepted September 10. Reprint requests: Dr. Kong, Cedars-Sinai Medical Center, Division of Pulmonary and Critical Care Medicine, Room 6732, 8700 Beverly Blvd., Los Angeles, CA 90048.
patients with COPD that there was "insufficient data to establish the duration of hospitalization in individual patients to achieve maximal benefit," although they did list some criteria that they admitted as being supported by limited data and consensus. 6 The guideline, however, lacks the specificity to improve the efficiency or quality of care beyond current medical practice or to alter physician practice patterns. Guidelines should be explicit and substantive, and preferably based on outcomes data, to affect physician practice significantly and favorably. 7 •8 A recent study by Mushlin and colleagues 9 demonstrated that the necessary lengths of stay for patients with COPD may be significantly less than actual lengths of stay. 9 The study de monstrated that 90% of patients with COPD were free of complications or the need for monitoring after 6 hospital days, although these patients remained hospitalized for an average of 8.7 days. However, this study was limited by a relatively small sample size (n=83). Therefore, we retrospectively studied a practice guideline that identified "low-risk" patients admitted CHEST I 111 I 1 I JANUARY, 1997
89
to the hospital with exacerbation of COPD that could potentially safely reduce their length of hospital stay. The retrospective study showed that the guideline had potential for saving many hospital days by early discharge of low-risk patients and did not appear to compromise quality of care. This guideline was then implemented prospectively on low-risk patients admitted to the hospital to assess its impact on length of stay and quality of care.
MATERIALS AND METHODS Methods
The study was a retrospective analysis of patients hospitalized with exacerbation of COPD. Patients were classified at low risk for development of complications accordin g to the guideline. We investigated the potential effects of the guideline in recommending a 3-day length of hospital stay and on quality of care. We then went on to determine if the practice guideline studied would have an impact on shortening length of stay while maintaining or improving quality of care. Description of the Institution
The study was performed at Cedars-Sinai Medical Center, a large teaching community hospital that serves west Los Angeles. Most hospitalized patients are cared for by physicians in private practice. Description of Patients
We analyzed patients over th e age of 45 years who were consecutively hospitalized with worsened dyspnea di agnosed as exacerbation of COPD over the period of January 1992 to March 1993. We chose charts of patients from the hospital discharge database and selected according to the Ninth Revision of the International Classification of Diseases codes. 10 These codes are listed in Appendix l. Sixty percent of all the reviewed charts met the inclusionary criteria and were ente red into th e study. Patients were excluded from the study if th ey had pulmonary diagnoses at th e time of hospital admission other than or in addition to COPD---eg, pulmona1y embolism, pneumonia, bronchiectasis. Patients were also excluded if the primary reason for hospital admission was not exacerbation of COPD (eg, urosepsis, abdominal pain), if they had severe congestive heart fai lure ( New York Heart Association class IV), if they had chest pain consistent \vith myocardia\ si chemia, or if they were intubated and ventilated on the day of admission. Practice Guideline
Afte r a r veiew of the medical lite rature, 9 • 11 the practice guideline was formalized by consensus within a study group comprised of two internists and a pulmonologist. The guideline stated that patients who had none of th e following complications at 72 h after hospitalization were placed in a low-risk category and were potentially suitable for early discharge. These complications are listed in Appendix 2. Furthermore, patients who developed major complications (Appendix 3)12 during the first 72 h of hospitalization were unsuitable for conside ration for early discharge and hence excluded from th e study.
90
Definition of Need for Continued Hospitali;:;ation
The occurrence of a significant medical complication, as described above, after the third hospital day served as a marker for the need for continued hospitalization. After a complication was identified, the need for continued hospitalization was determined by hvo physicians' implicit judgment. The physicians judged that continued hospitalizati on was necessary when a patient developed a complication th at may have benefited from continued hospitalization. Continued hospitalization was considered potentially unnecessary if th e patient had an uncomplicated hospital course. This method of quality of care review had been used in several previous practice guideline validation studies.l3. 14 Complications Explicit RetJiew: Complications were abstracted from th e medical record by the research fellow. Patients who were determined to be at low risk on th e fourth hospital day and who then suffered the above-defined complications after that day were considered to be potentially misclassified by th e guideline. The potential misclassifications were th en submitted to the physicians for implicit review. Implicit Revieu;: All complications occurring in low-risk pati ents on and after the fourth hospital day we re implicitly and independently reviewed b y hvo physicians (a board-certi fied inte rnist and a board-certified pulmonologist) who were not blinded t o th e patient's risk status. The physicians rated whethe r discharge horne would have worsened quality of care, that is, patient outcome may have been compromised h ad th e patient been home at the time of the development of the compLication. These outcomes included potential need for e mergency department intervention or rehospitalization with the development of the complication \vi thin 7 days of hospital discharge. In cases of disagreement, th e judgment of the physician who felt that the guideline wou ld have worsened quality of care was used as the "gold standard," hence using the most conservative definition possible. Calculation of Lengths of Stay
The expected benefit in bed utilization afford ed b y the guideline was the projected reduction in hospital bed-days. For each low-risk patient, the hypothetical number of hospital bed-days saved was estimated had the guideline been used to prescribe patient care. The number of bed-days saved was defined as the actual number of days in the hospital less the number of days in hospital recommended by the practice guideline. Prospective Guideline Intervention
After formali zation of the guideline, the case manager d edicated to the respiratory ward was briefed on the inclusion and exclusion criteri a of the practi ce guideline. The study was then presented and approved by the institutional review board for implementation. A letter was sent out to all internal medicine and pulmonary attending staff outlining the clinical practice guideline and its aims prior to the start of th e study. The study was then implemented in an alternate month intervention and control time series over a period of 12 months. Intervention M ethod
Low-risk pati ents admitted to th e respiratory floor with exacerbation of COPD were identified by the case manager and admitted into the study. The intervention was as follows. Clinical Investigations
(1) At 48 h postadmission, a letter was placed in the file informing the attending physician that his or her patient was low risk and was suitable for discharge after 72 h of hospitalization , if no complications developed in the preceding 24 h. (2) On revisit, if there were no plans to discharge the patient at the appropriate time, the physician would be contacted by the case manager and reasons elicited for maintaining in-patient care. The case manager would be supp01ted by a physician if necessary in cases where there was no apparent good reason for keeping a patient in hospital. (3) After hospital discharge, the patients would be interviewed by telephone and sent a Medical Outcomes Study SF-36 questionnaire between 1 and 3 months postdischarge, and any mortality or morbidity data would be obtained from the attending physician and chart review.
100
98 96
/o
0
94 92 90 88
Control Method
Low-risk patients admitted during the control months were identified by the case manager and recorded. After hospital discharge, the control low-risk patients would be followed up as outlined in step 3 above. The list of all patients admitted to the target ward was obtained and the charts of all the patients who had the appropriate International Classification of Diseases (ninth revision) discharge diagnoses were reviewed b y the investigator (G.K.K. ) who was blinded to the risk status of the patients as noted by the case manager. Statistical analysis was performed using a software package (True-Epistat).l 5 Nonpaired two-sided t tests were performed with p< O.OS used as the el vel of statistical significance. RESULTS
Retrospective Analysis Demographics: A total of 250 patients were included in the study. Medical records were available for abstraction on 97.8% of eligible patients. The average age of the study patients was 71.5 years (SD, 11.6). Women accounted for 68% of the patients. The mean hospital length of stay was 6.5 days (SD, 4.8). The outcomes of the patients were as follows : 94% discharged to home; 4.4% transferred to another facility; and 1.6% deaths. The proportion of patients classified as low risk according to th e guideline during each hospital day is represented in Figure l. Projected Effects of the Practice Guideline on Bed Utilization: A total of 94.8% of the patients would have been classified as low risk according to the guideline by the fourth day of hospitalization and hence suitable for consideration for early discharge. The estimated lengths of stay using the guideline to discharge low-risk patients after 3 hospital days was 3.2 days. As the average length of stay for these patients was actually 6.5 days (SD, 4.8), the number of bed-days saved p er patient had the guideline been used would have been 3.3 days. On an annual basis, the number of bed-days saved would have been 627 days on a projected annual number of 190 low-risk patients.
86
2
4
6
8
10
12
Days from admission (1 being day of admission) FIGURE l. Percentage of patients who were found to be a t low risk from the day of hospital admission and onwards.
Explicit and Implicit Judgment of Quality of Care: The percentage of the low-risk patients who suffered any of the defined complications after 72 h of hospitalization was 1.9% (four patients) with a 95% confidence interval of 0.3 to 3.6%. These patients' charts were then independently reviewed by an internist and a pulmonologist and it was judged by one that only three (1.4%) would have suffered worsened quality of care if the patient had been discharged according to the guideline, while the other physician agreed with the explicit judgment that all four patients would have worsened quality of care had they been discharged according to the guideline. This would translate to a hospital readmission rate of only 1.9%. The accuracy of the guideline when used for discharging low-risk patients after 3 days of hospitalization was 98.1 %. The 95% confidence interval was 96.4 to 99.7%. Prospective Study One hundred twenty-four COPD patients were admitted to the respiratory ward during the study period (Table 1). Only 24 patients (19%) were correctly identified as low-risk patients and entered into the study-these were the true-positives. Thirty patients (24%) were low-risk patients who were not identified for inclusion into the study-these were the false-negatives . Sixty-two patients (50%) were not included into the study because the written diagnoses at the time of case manager review did not mention COPD exacerbation, but the discharge diagnosis was one of exacerbation of obstructive airways disease-the true-negatives. Fifty-six perCHEST I 111 I 1 I JANUARY, 1997
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Table !-Effectiveness of Case Management in Identifying Patients With COPD Exacerbation Who Were Considered to be at Low Risk*
Patient Truly at Low Risk According to Guideline Yes No
Case Manager Judged the Patient to be at Low Risk According to the Guideline* Yes , %
No,%
19 (n =24) 2 (n=3)
24 (n=30) 50 (n=62)
*Total n =124; five of th e charts (5%) were unavailable for review.
cent of these "true-negative" patients (35 patients) should have been included as low-risk patients, but they were excluded because diagnoses other than COPD exacerbation were placed in the chart during the first 3 days of hospitalization. Three patients (2%) were incorrectly identified as low-risk patients-the "false-positives." Overall, 65 of these 124 admissions (52% ) were low-risk patients who were not identified for inclusion into the study. The month-by-month length of stay for the lowrisk patients (the true-positives and the false-negatives ) are presented in Figure 2. The mean length of stay during all control months was 4.3 days. The mean length of stay during all intervention months was 3.7 days (p=O.ll6). The mean length of stay for all patients was 4.0 days. The mean length of stay for patients correctly identified by the case manager and in whom there was active intervention was 3 days (n=l4). There was no statistically significant difference in the results of the outcomes between the control and intervention groups (Table 2).
6 en
in'
Cl .~
--
5 4
>.
ctl
en
3
0
.I:
0>
c
2
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1
Control versus Intervention Months FIGURE 2. Comparison of lengths of stay in control (white bars ) and intervention (dark bars ) months. No statistical differe nce (p =O. ll6).
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Table 2-0utcomes of Patients Included in the Study* Variable
Control
Intetvention p Value
66.6±12.4 70.7::+::10.6 Age, yr Percentage female 45 59 3.7 4.3 Mean LOS, 1 d 0 0 Mortality 0 Transfer to highe r-level care: 0 Survival 1 mo postdischarge 11/11 = 100% 16/16=100% 11/11 = 100% 16/16= 100% Discharge to home Quality of life domains 35::+::35 42::+::33 Physical fun ction 17::'::41 Physical role 11 ±33 55::+::28 77::+::33 Bodily pain 60::+::27 General health 52::+::19 49::'::25 41±20 Vitality/energy 71::+:: 37 57::+::39 Social function 50::+::54 59::+::49 Emotional role 66::'::17 66::+::18 Mental health
0.27 0.42
0.70 0.78 0.19 0.51 0.50 0.48 0.74 0.97
*Total number=27; control, n =ll; intetve ntion , n=16. LOS = length of stay.
1
DISCUSSION
Patients hospitalized with exacerbation of COPD are commonly treated in the short-term care setting for approximately 6 to 8 days, although there is little evidence to suggest that this length of stay is necessary for all patients. 9 The retrospective study demonstrates that when patients are classified as low risk according to our guideline, the hospital length of stay could potentially be shortened to 3.2 days, with probably little effect on quality of care. As a consequence of this shortening of length of hospital stay, this guideline may reduce hospital costs. During the first 3 days of hospitalization, an increasing amount of data becomes available to the physician as to the progress of the patients-whether their conditions are improving or deteriorating. This guideline gives the physician objective criteria with which to identify patients who are at low risk for developing further complications related to their illness, and allows the physician to decide on the suitability of early discharge for his or her patient, without compromising quality of care. Mushlin et al 9 identified some factors that suggested which patients were less likely or more likely to require prolonged inpatient management. Other authors have identified factors that affect the longterm prognosis of patients with COPD, but none of these studies have been translated into a practice guideline that can be used to safely discharge patients who are at low risk for complications. 16-23 This particular guideline identifies a subset of low-risk COPD patients who can safely be discharged after 3 days of treatment in hospital. Many guidelines are developed using expert opinClinical Investigations
ion and literature review without evaluation of their impact on outcomes such as quality of care and health-care costs. 24 The development of a practice guideline also does not guarantee that it will be accepted and used by physicians in clinical practice. The testing of a guideline in a retrospective study provides some evidence for its safety and effectiveness (as was done in this study), and may facilitate its acceptance by practicing physicians. 25 However, as with the introduction of a n ew drug into clinical practice, the guideline needs to be validated in a prospective clinical trial before it can be recommended for widespread implementation. This guideline was therefore studied in a prospective controlled trial using an alternate month intervention/control time series. Based on the retrospective data, we projected a savings of over 3.2 bed days for low-risk patients admitted to the hospital with exacerbation of COPD. Several problems prevented us from reaching our target, although when implemented, the guideline did result in shorter stays without detracting from the patient's health status or satisfaction with care. The problems were as follows: (1) There was a failure to capture all patients on admission because of inaccuracy of written diagnosis. Patients whose charts did not expressly contain the word COPD exacerbation (35 patients) were excluded, and many who were labeled on admission as "asthma exacerbation," "bronchospasm," "exacerbation of asthmatic bronchitis," "rule-out pneumonia," "rule-out CHF" turned out to be low-risk patients with COPD exacerbation on chart review. These patients accounted for the majority of the patients excluded from the study. (2) There was a failure to capture patients even when all inclusion criteria were identified. Thirty patients (24%) who satisfied all criteria were not identified by the case manager. (3) There is a secular trend in southern California that has resulted in shortening of length of stays for COPD exacerbation even without intervention of the case manager and the use of the guideline. The intervention of the case manager in those cases that were correctly identified did result in a small decrease in length of stay. However, this difference was so small as to make the cost-benefit of the guideline minimal. Despite the shorter length of stay for all patients, we showed that less hospital days did not adversely affect clinical outcome. Potential Solutions
The inclusion criteria for the low-risk patients should be broadened to include all patients over the age of 45 years who have the various diagnoses in the chart synonymous with exacerbation of chronic air-
flow obstruction (eg, asthma exacerbation, asthmatic bronchitis, bronchospasm, who had been excluded in the prospective study), and not to exclude the "ruleouts" that may turn out to be exacerbation of airflow obstruction later on in the course of the hospitalization. Closer interaction between the physicians and case managers may improve the number of low-risk patients identified by the case manager, although this may increase indirect costs associated with guideline implementation in terms of physician and case manager labor costs. In conclusion, this study emphasizes the importance of prospective evaluation of guidelines before implementation. Failure to do so could result in inadequate guidelines that have no impact on achieving the desired outcome. ACKNOWLEDGMENTS: We would like to thank Patricia Hobson, RN , Susan Edinger, RN, and Mary Reidinger, RN , for assistance in the collection of prospective data and with the statistical analysis.
APPENDIX
1
International Classification of Diseases COPD and Allied Conditions 490-Bronchitis, not specified as acute or chronic (3%) 491-Chronic bronchitis (28%) 491.0-Simple chronic bronchitis 491.1-Mucopurulent chronic bronchitis 491.2-0bstructive chronic bronchitis- with and without exacerbation 492-Emphysema (10%) 493-Asthma 493.2-Chronic obstructive asthma (16%) 493.9-Asthma, unspecified (18%) sewhere classified (25%) 496-Chronic airways obstruction, not el (The number in parentheses represents the percentage of charts with each code.) APPENDIX 2
Minor Complications at 72 Hours of Hospitalization l. Dehydrati on Serum sodium level >155 mmol and/or a urea/creatinine ratio of > 20. 2. Hypotension Systolic BP >90 mm Hg or a >40 mm Hg reduction of BP from baseline. 3. Respiratmy acidosis An arteri al blood pH <7.30. 4. Hypoxemia on room air An arterial blood Po 2 <55 mm Hg or pulse oximetry saturation <88%. This rule applied unless the pati ent was known to be chronically hypoxic from history, that is the patient had a Po 2 <55 mm Hg under normal circumstances. 5. Hypercapnia An arterial blood Pc o 2 >45 mm Hg. This rule applied unless the patient was known to be chronically hypercapnic from history, that is the patient had a Pco 2 > 45 rnm Hg under normal circumstances. CHEST / 111 / 1 I JANUARY, 1997
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6. Fever A temperature >38.3°C. 7. Development of a new infiltrate on the chest radiograph. 8. Inability to take food, fluids, or oral medications. 9. Development of new atrial or supraventricular tachyarrhythmias. 10. Poor functional status of the patient. This information was obtained from daily nursing assessment of patient's ability to perform activities of daily living, and nursing (and medical, when available) assessment of higher mental function.
APPENDIX
3
Mrqor Complications at 72 Hours of Hospitalization Pneumothorax. Ventricular fibrillation or ventricular tachycardia. Need for intubation and mechanical ventilation. New onset C!\S event, ie, cerebrovascular accident GI hemorrhage New-onset chest pain consistent with the diagnosis of myocardial ischemia. 7. Proximal deep venous thrombosis. 8. Pulmonary embolism. 9. Onset of acute renal failure-increasing BUN and creatinine that was not secondary to dehydration or obstruction. 10. Septic shock. Defined as sepsis (Ame rican College of Chest Physicians/Society of Critical Care Medicine Consensus Conference Definition ) with hypotension-a systolic BP <90 mm Hg or a reduction >40 mm Hg from baseline BP in the absence of other causes for hypotension despite adequate fluid resuscitation. 12 11. Cardiorespiratory arrest necessitating res uscitation. 12. Death.
l. 2. 3. 4. 5. 6.
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7 Lomas J, Anderson GM, Dominick-Pierre K, et al. Do practice guidelines guide practice?: the effect of a consensus statement on the practice of physicians. N Eng! J Med 1989; 321:1306-11 8 \Veingarten SR. The development, implementation, and evaluation of practice guidelines: a case example. Proceedings of the 41st Annual Group Health Institute. New York: 1991; 757-67 9 Mushlin AI, Black ER, Connolly CA, et al. The necessary length of hospital stay for chronic obstructive pulmonary disease. JAMA 1991; 266:80-3 10 International Classification of Diseases, 9th revision, clinical modifications. 4th ed. Salt Lake City: Med-Index Publications, Utah. 1993 ll Weingarten SR, Reidinger MS, Varis G, et al. Identification of low- risk patients hospitalized with pneumonia: implications for early conversion to oral antimicrobial therapy. Chest 1994; 105:1109-15 12 American College of Chest Physicians-Society of Critical Care Medicine Consensus Conference. Standardizing terminology in sepsis and multi-organ failure: definitions of sepsis. Northbrook, Ill, August 16-18, 1991 13 Donabedian A. Explorations in quality assessment and monitoring. (vol 2). Ann Arbor, Mich: Health Administration Press, 1982; 19-21 14 Weingarten S, Ermann B, Bolus H, et al. Early "step-down" transfer of low-risk patients with chest pain: a controlled interventional trial. Ann Intern Med 1990; 113:283-89 15 Gustafson TL. True epistat. H.ichardson, Tex: Epistat Services, 1992 16 Burrows B, Bloom }\\1, Tarver GA. The course and prognosis of different forms of chronic airways obstruction in a sample from the general population. N Eng! J Med 1987; 317: 1309-14 17 Anthonisen NR, Wtight EC, Hodgkin JE. Prognosis in chronic obstructive pulmona1y disease. Am Hev H.espir Dis 1986; 133:14-20 18 Ashutosh K, Dunsky M. Noninvasive tests for responsiveness of pulmonary hypertension to oxygen: prediction of survival in patients with chronic obstructive pulmonary disease and cor pulmonale. Chest 1987; 92:393-99 19 Boushy SF, Thompson HK, North LB. Prognosis in chronic obstructive pulmona1y disease. Am Rev H.espir Dis 1973; 108:1373-82 20 Johnston HN , McN eil HS, Smith DH. Chronic bronchitismeasurements and observations over 10 years. Thorax 1976; 31:25-9 21 Kanner RE, Henzetti AD, Stanish WM. Predictors of survival in patients with chronic airflow limitation. Am J M ed 1983; 74:249-55 22 Kawakami Y, Kishi F, Dohsaka K. Heversibility of chronic obstructive pulmonary disease. Chest 1988; 93:49-53 23 Kok-Jensen A, Sorenson E, Damsgaard T. Prognosis in severe chronic obstructive pulmonary disease. Scand J H.espir Dis 1974; 55:120-28 24 Audet AM , Greenfield S, Field M. Medical practice guidelines: current activities and future directions. Ann Intern Med 1990; 113:709-14 25 Selker HP. Criteria for adoption in practice of medical practice guidelines. Am J Cardiol 1993; 71:339-41
Clinical Investigations