A Comprehensive Quality Assessment Program on the Autopsy Service

Transcription

1 A Comprehensive Quality Assessment Program on the Autopsy Service ALAN R. SCHNED, M.D., R. PETER MOGIELNICKI, M.D., AND MARTHA E. STAUFFER, M.D. Many previous studies have established the value of the autopsy in assessing clinical diagnostic accuracy. None has described, however, the use of the autospy as an ongoing, prospective audit of clinical and pathologic performance. The authors herein outline the process and report the initial results of a comprehensive quality assessment program on their autopsy service. Particular emphasis was placed on evaluation of the responsiveness of the autopsy to clinical questions and interests. The four parts of the overall program included an epidemiologic survey of causes of death in the authors' patient population, a determination of the clinical significance of autopsy findings, an assessment of clinical factors that may have contributed to death, and a quality control mechanism of the autopsy itself. The process can be adapted to a variety of hospital settings. (Key words: Autopsy; Clinical diagnosis; Quality assessment; Quality Control) Am J Clin Pathol 1986; 86: THE VALUE of the autopsy in assessing accuracy and error in clinical diagnosis has been demonstrated repeatedl y 2,3,6,13,15,26,29,30 s evera i rep 0 rts also have shown that the autopsy is a useful tool for tracking error rates over time. 12 " 14 Despite serving these important functions, however, the autopsy has had a pronounced decline both in numbers and in perceived significance. 27 ' 28 One of the major explanations given for this decline is that the autopsy is too often poorly performed and too often neglects to address issues of clinical concern. 17 ' 22,25 ' 27 This problem has contributed to the perception by many clinicians that the autopsy is unhelpful, irrelevant, and/ or outmoded. Unlike many other problems, this can be confronted directly. In so doing, the pathologist must assure that the autopsy is performed and reported satisfactorily, demonstrate that it is responsive to the questions of clinicians, and prove that it is useful and meaningful. A well-conceived quality assessment program can help achieve these goals. We herein report our experience with a comprehensive prospective quality assessment program on our autopsy service, performed in close collaboration with our clinical colleagues. We have been governed by the conviction that it is critical for pathologists to know how responsive the Received May 20,1985; received revised manuscript and accepted for publication February 19, Presented in part at the ASCP/CAP Meeting, Chicago, Illinois, April Address reprint requests to Dr. Schned: Laboratory (113), Veterans Administration Medical Center, White River Junction, Vermont Departments of Pathology and Medicine, Veterans Administration Medical Center, White River Junction, Vermont, and Dartmouth Medical School, Hanover, New Hampshire autopsy is to clinicians' interests. Without feedback of this nature as a basis for improvement, efforts to enhance the autopsy's image are unlikely to succeed. Materials and Methods The White River Junction Veterans Administration Medical Center is a 225-bed major teaching component of the Darmouth-Hitchcock Medical Center. Between 1948 and 1970 the average autopsy rate was 91.1%; since 1970 the average rate has been 75.9%. Autopsies are performed by pathology residents under the supervision of the staff pathologist. In January 1983 we began a program of quality assessment (QA) on the autopsy service, which is incorporated into a preexistent weekly Organ Review, a presentation of gross autopsy findings directed to, and usually well-attended by, clinical staff, house staff, and students. Clinical pathologists and radiologists usually are present. Patient records and radiologic studies for each case are available for review. Immediately following presentation of each case, a QA form, outlined below, is completed by the staff pathologist in conjunction with the appropriate clinical service chief. Occasionally, conclusions reached at Organ Review are amended after microscopic examination. A formal policy of informing patients' families of autopsy findings does not exist, although some clinicians routinely write letters to next of kin, summarizing autopsy findings. The QA form consists of the following four parts. Part I: Underlying Disease and Cause of Death Both the underlying disease and the ultimate cause or causes of death are recorded for each case in this part. Part II: Clinical Significance ofautopsy Findings Each case is assigned to one of five possible primary categories depending on whether the autopsy: 133

2 134 SCHNED, MOGIELNICKI, AND STAUFFER A.J.C.P. August 1986 Table 1. Causes of Death for Major Underlying Disease Categories Major Disease Category Neoplastic Cardiac/coronary Chronic lung disease Cirrhosis No. (% total) 65 (59) 15(14) 10(9) 9(8) Cause of Death Infection Pneumonia Sepsis Opportunistic infection Massive metastatic spread Myocardial infarction Arrhythmia or pump failure Pneumonia Gastrointestinal hemorrhage No. (%) 42 (64) 34 (52) 4(6) 4(6) 12(18) 5(7) 10 (67) 7(70) 4(44) (1) Uncovers a major disagreement in diagnosis. (2) Establishes a major unsuspected or additional diagnosis. (3) Provides significant clarification of a differential diagnosis. (4) Confirms or verifies the major diagnosis. (5) Is indeterminate, without clarifying or resolving the major diagnostic issue. Primary assignment to category (4) does not exclude secondary assignments to one of thefirstthree categories. In addition, a case also may be assigned to a sixth category if the autopsy: (6) Provides significant incidental or secondary information unrelated to the major diagnosis or cause of death. In category (6) significant incidental information is subclassified as follows: (A) Clinically relevant: 1. Provides answers for specific therapeutic protocols. 2. Yields information on treatment effects {e.g., eradication of disease, complications, etc.). 3. Gives feedback on diagnostic modalities (e.g., radiologic, endoscopic, laboratory, etc.). (B) Primarily pathologic feedback. Part HI: Clinical Factors Contributing to Death Each case is assigned to one of four categories: (1) Death due to the irrevocable course of the disease (i.e., no major contributing factors). (2) Death due to error in clinical judgment or treatment plan. (3) Death due to a complication of a therapeutic procedure. (4) Death due to inattention to, or misinterpretation of, diagnostic tests. Part IV: Performance Assessment of the Autopsy This part is divided into three sections. In thefirstsection, all questions raised by the clinicians prospectively at the time of case presentation at Organ Review are recorded on the QA form. Many answers are recorded directly at the time of gross presentation, but others require subsequent microscopic evaluation, brain cutting, finalization of microbiologic cultures, etc. In the second section, a specific gross diagnosis is recorded at Organ Review for a given lesion, if (1) the lesion occasions controversy among the pathologists present; (2) the diagnosis is not patently obvious; or (3) the gross pathologic diagnosis is considered particularly challenging. Subsequently, the final histopathologic diagnosis is compared with the gross diagnosis. In the third section, any and all premortem pathologic diagnoses (including all biopsies, surgical resections, cytologic material, and bone marrow examinations) are compared with final postmortem diagnoses. Diagnoses are judged to show either no significant discrepancy or a major contradiction or variance. Results In autopsies were performed, an autopsy rate of 59.6%. Parti Table 1 presents an abbreviated list of causes of death in the most frequently encountered major disease categories. Part II There was a major disagreement in diagnosis or unsuspected diagnosis in 14 cases, or 13% (Table 2). In these cases the missed diagnosis was judged to have a significant impact on therapy or outcome. In addition, in one case there was a significant disagreement in one facet of a complicated case, but autopsy otherwise confirmed the major underlying diagnosis. In ten cases major unsuspected diagnoses were uncovered but were deemed not significant enough to have altered the major therapeutic thrust. Of the 43 cases that provided incidental or additional information, secondary to the main diagnostic considerations, 26 were among the 79 in which autopsy otherwise confirmed the major diagnosis. Thus, combining all cases in which autopsy demonstrated a disagreement in diagnosis, uncovered an unexpected diagnosis, or clarified a differential diagnosis (i.e., both columns in categories 1,

3 Vol. 86 No. 2 QUALITY ASSESSMENT OF AUTOPSY SERVICE Table 2. Clinical Significance of Autopsy Findings 135 Significance Category Major Diagnosis No. Cases (%) Minor Diagnosis No. Cases (%) 1. Major disagreement in diagnosis 2. Unsuspected or additional diagnoses KD 13 (12) 14(12) 1(1)* 10 (9)* 3. Clarification of differential diagnosis Diagnosis suspected but not confirmed Diagnosis among 2 or more equally considered 4. Confirmation of major diagnosis 5. Indeterminate autopsy (71) 4 (4)f 7(6) 6. Significant incidental or additional information Answers for therapeutic protocols Information on therapy effects Feedback on diagnostic tests or procedures Important pathologic feedback (39) * See text under "Results." t In one case an etiology was obscured by prolonged therapy effects; in one case a primary origin for metastatic carcinoma was not resolved; in two casees uncertainty probably related to pathologist deficiencies. 2, and 3 in Table 2), and adding the 26 cases with incidental information in otherwise confirmatory autopsies, a total of 72 autopsies or 64% provided more than purely confirmatory clinical information. Part III Table 3 summarizes the clinical factors contributing to death in our series. The three judgmental or treatment errors included failure to transfer the patient to intensive care due to underestimation of the severity of cardiac disease, failure to biopsy a metastatic malignancy of presumed pancreatic origin that proved at autopsy to be pulmonary small cell carcinoma, and failure to anti-coagulate prophylactically after total hip surgery. Four of the therapeutic complication deaths occurred after surgery. The other three deaths in this category were the result of hepatic infarction as a complication of therapeutic embolization for massive gastrointestinal hemorrhage, sepsis from an infected intravenous catheter, and severe hyponatremia that developed during transurethral resection of the prostate. Among the five cases in which evidence for a major clinical diagnosis was misinterpreted or ignored, four resulted from failure to respond fully to patient complaints or the clinical course itself. In one case radiologic interpretation was judged inaccurate. Pari IV Two hundred four questions were posed prospectively in 99 of the 111 autopsies. The range was 1-5 questions; the average was 2.1 questions per case. Definitive answers were provided to 185 of these questions, or 91%. Nineteen questions (9%) were not definitively answered. Most of these failures could be grouped into several common categories: (1) Three cases in which the pathologist could not distinguish between two or more possible anatomic explanations for a given clinical finding. (2) Six cases in which a metabolic, toxic, or drug-related cause could be implicated but not proved to explain a clinical finding. (3) Three cases in which questions were directed to clinical events that occurred weeks or months before death, such that diagnostic evidence had either resolved or was obscured by effects of intervening therapy or healing. (4) Three cases in which failure to answer a question definitively reflected a failure of the prosector to do a meticulous enough gross evaluation, to sample a tissue not saved in stock, or to address a specific issue pointedly enough at the time of dissection. In 12 cases no clinical questions were asked. In all 12 cases, autopsy mainly confirmed the major clinical di- Table 3. Clinical Factors Contributing to Death Category Number (%) 1. Irrevocable course of disease 2. Error in judgment or treatment 3. Therapeutic complication 4. Unrecognized exisitng evidence of disease 95 (86) 3(3) 7(6) 5(5)

4 136 SCHNED, MOGIELNICKJ, AND STAUFFER AJ.C.P. August 1986 agnoses. A major secondary diagnostic error, however, was uncovered in one case, and significant incidental or secondary information was provided in five other cases. One hundred two gross lesions in 68 autopsies were included in the test of gross diagnosis skills. Seventy-six gross diagnoses (75%) were confirmed by microscopic study, while 26 (25%) were found to be incorrect or incomplete. A comparison of postmortem pathologic diagnoses could be made with a total of 53 premortem pathologic diagnoses in 48 autopsies. There was no significant discrepancy between premortem and postmortem diagnoses in 47 instances (89%). In six cases (11%) autopsy diagnosis either contradicted or did not completely conform to a premortem pathologic diagnosis. In two cases there was a discrepancy with a cytologic interpretation one was a probable false positive sputum following combined radiotherapy and chemotherapy, and the other was a probable false negative ascitic fluid in a patient with intraperitoneal spread of adenocarcinoma. In the other four cases autopsy clarified or established an origin or cell type for what had been recognized premortem only as a poorly differentiated neoplasm. Suggested primary sites in these cases either had not been offered (two cases) or were found to be incorrect at autopsy. Discussion A paradox exists between the increasing concern with quality assurance in medical practice and the virtual absence of prospective QA mechanisms on autopsy services. This is so despite claims that the autopsy is the "... key to quality control in medical care," 16 "... a yardstick for clinical diagnoses," 6 and "... the ultimate audit."" Many previous studies have clearly established the value of the autopsy in assessing clinical diagnostic accuracy ' ' 18,23 ' Virtually all of these studies, however, have been self-limited or finite, although the study period in a few has spanned years 7,14 or even decades. 13 We believe our study is the first to describe a process of ongoing, comprehensive QA on an autopsy service. It is designed as a long-term, open-ended monitoring of both clinical and pathologic performance. We are motivated to present this outline of our program, not as a definitive format, but only as an example of a process of QA that has been successfully introduced and accepted at our hospital. We hope it might stimulate refinements or totally new efforts to use the autopsy as a prospective QA tool. We incorporated the program into a preexisting, wellattended weekly Organ Review of autopsied cases because this forum provided a convenient opportunity for dialogue and obviated additional time commitments. A standardized checklist-type form was devised to promote efficient recording of data. To help confer objectivity and legitimacy, we deliberately involved our clinical colleagues closely. 2,3,6,13,26 Perhaps most importantly, we opted to conduct our program prospectively, as have only a few others. 3 ' 5,6,9 In our opinion, the major flaw with a retrospective approach is that it cannot be used to assess how responsive the autopsy is to the specific queries and interests of clinicians. 2,4,l3-1518,23,26,29,32 Thus, our motivation in establishing a prospective process was to address the perceived utility of the autopsy by clinicians. 9 Each of the several parts of our program was designed to address a different issue of quality assurance. Some elements of the program qualify as bonafidequality control, whereas others constitute a less formal but organized method of gathering performance data. Part I was designed to provide a breakdown of the kinds of disease and causes of death encountered on our autopsy service. It was intended as a minimum to provide basic population characteristics. But we also hope it eventually may give us insight into changing patterns of death at our hospital, much as Goldman and associates gained over decades with similar internal data. 13 This objective will require regular analysis of compiled data and is as yet unfulfilled. In Part II, one goal was to establish a mechanism of medical audit that would provide internal feedback on diagnostic accuracy and error rates. A second purpose was to determine how the autopsy in our hands contributes to better understanding of clinical problems. Thus, our design strategy was to consider all the possible ways the autopsy could provide feedback on the major clinical diagnoses in an individual case. Much of our data can be only roughly compared with previous studies because of well-recognized problems of nonstandardization. 3,28 Nonetheless, 13% of our cases represented a major disagreement in diagnosis or a major unsuspected diagnosis. By comparison, in a tabulation of the results of 12 previous studies, the proportion of cases with substantial discrepancies (i.e., discrepancies with impact on survival) ranged from 4.0 to 18.7%.' A further 10% of our cases represented incorrect or missed diagnoses with therapeutic or prognostic significance but in which the major underlying diagnosis or cause of death was confirmed. These cases do not readily conform to any one of the four classes of missed diagnoses defined by Goldman and colleagues, 13 but are probably comparable to class 3 discrepancies as proposed by Anderson. 1 Our results also showed that, while the autopsy confirmed the major clinical diagnosis in 71% of cases, more than purely confirmatory diagnostic information also was provided in nearly the same percentage (64%). This figure is quite comparable to data compiled in the three previous

5 Vol. 86 No. 2 QUALITY ASSESSMENT OF AUTOPSY SERVICE 137 studies that addressed the overall yield of information from autopsies. 4 ' 018 These examples from the literature and our own study emphasize the breadth of the role the autopsy plays in providing clinical feedback. In the category of indeterminate autopsies, our data cannot be compared with other reports. Most retrospective studies do not even acknowledge the existence of indeterminate or inconclusive autopsies. The only allusions we could find to this problem were as follows: in Wilson's study, in about 20% of cases "... more or less mystery and confusion still prevailed after the postmortem examinations" 32 ; Clark's remarkable record of only one failure to identify a cause of death in a series of 1,076 autopsies 7 ; and Holler and DeMorgan's exclusion of seven cases from their study because the autopsy failed to explain the cause of death. 18 It is remarkable that this issue of indeterminacy has not been acknowledged more often, because the frequent failure of the autopsy to resolve or even address important clinical questions has been cited as an important factor contributing to the perception of the autopsy as irrelevant or unhelpful It should be emphasized that our figure of four indeterminate autopsies included only those unanswered problems that were central to the purpose of procuring an autopsy; in Part IV of our program we found that 9% of the total clinical questions were not satisfactorily answered (vide infra). We also realized that another four cases were originally considered indeterminate at the time of Organ Review presentation but were later recategorized after microscopic review. Obviously this situation can lead to a greater perception of indeterminancy than actually exists. We have reacted to this finding by doing more selected rush microscopic and frozen sections before conference in order to project more conclusive information. In Part III of our program we attempted to uncover possible clinical factors that contributed to death, in large part to establish baseline performance standards at our hospital. The definition of acceptable limits and the establishment of such standards are essential steps in meaningful QA. 1,28 It remains to be seen, however, whether actual relevant clinical care recommendations can emanate from such observations. 21,31 In our series a potentially avoidable or remediable factor contributed to death in 14% of cases. One-third of these were postoperative complications. This fraction probably falls within acceptable limits for the volume and extent of surgery performed at our hospital, although continued surveillance of these data will be necessary. The remaining cases (8%) involved errors in judgment or misinterpretations of existing clinical data, a figure very similar to previous published results. 11,14 In Part IV we attempted to develop a process of quality control of the autopsy itself. It was designed to assess our own skills and accuracy in autopsy performance. We felt that pathologists must be willing to address both the inherent limitations of the autopsy and their own fallibility in its performance. Quality control of the autopsy can provide important feedback to the pathologist as the first step in improving performance. Perhaps just as importantly, it can also help build trust with clinicians by creating a sense of shared accountability. In the first section of Part IV, 9% of nonselected clinical questions, most seeking correlation with the clinical course, were not answered definitively. Some of the unanswered questions reflected an inherent inability of the autopsy to solve certain kinds of problems. Some questions were left unanswered, however, because of performer deficiencies. We attempted to categorize these unanswered questions in our series as the first step in analyzing the weaknesses of the autopsy as we perform it, much as did Fowler and colleagues previously. 9 This information would be of particular value in any attempt to triage autopsies by potential gain. Our test of gross diagnosis skills and the comparison of premortem and postmortem pathologic diagnoses were conceived primarily as simple mechanisms of internal quality control. The data from the gross diagnosis test are far too few for statistical analysis, but we feel they can provide useful crude information on selected lesions. Perhaps it can also lead to modifications in practice that could minimize workload. 15 The comparison of premortem and postmortem pathologic diagnoses complements and expands our program of internal and external slide audit and peer review that exists in surgical pathology.' 9,20,24 This comprehensive program of quality assessment has been received successfully in our hospital in large part because of existing clinician interest and support. Other favorable conditions at our hospital include an established Organ Review devoted to clinical-pathologic correlation, a dedicated hospital-wide program of quality control, and a tradition of unusually high autopsy percentage. Obviously a high autopsy percentage strengthens any conclusions reached regarding quality of clinical practice because it reflects a greater representation of all dying patients. We attribute our high autopsy percentage to several factors. First, we make a deliberate effort to publicize the desirability of obtaining autopsies. This includes regular reminders to the clinical house staff of our policy of pursuing autopsy permission in all deaths. Second, the autopsy is a highly visible educational instrument, with an autopsied case being the focus of a weekly medical morbidity and mortality teaching conference. Third, our attending staff is relatively stable, resulting in established relationships with patients and families spanning many years. We feel families tend to give permission for autopsy more readily to familiar, trusted caregivers. It might be added, however, that, although our autopsy

6 138 SCHNED, MOGIELNICKI, AND STAUFFER AJ.C.P. August 1986 percentage is much higher than the national average, our percentage has declined over two decades roughly at the same rate as those for most other institutions. We believe that the decline at our hospital is explained, in part, by the fact that many of the house staff come from institutions where the autopsy services are not very visible and the benefits and feedback potential of the autopsy are not emphasized. With their own poor perception of the autopsy, many of these house staff, no doubt, have trouble convincing their patients' next of kin of its value. The factors that help make this program successful in our hospital are obviously not universal. Thus, the specifics of the comprehensive program we have outlined might not be appropriate or feasible in all hospital settings. The process, however, is readily adaptable. Portions of the program can be modified, expanded, or reduced according to situation or need. For example, the clinical significance of autopsy findings might be preferably collected in conformance with a standardized outline, such as proposed by Anderson.' A concordance score, which expresses the extent of agreement between clinical and pathologic diagnosis, might be adopted for more precise and standardized evaluation. 10 Other areas of interest might be incorporated into such a program, whereas in some settings only a limited version might be more appropriate. We believe the advantages of this type of program are numerous. It introduces at least a crude mechanism for quality control of the autopsy, an area of anatomic pathology in which such monitoring has been neglected to date. 819 ' 20,24 It provides an ongoing, evolving surveillance of clinical diagnosis, with the potential of providing meaningful feedback information to clinical colleagues. It expands the concept of the autopsy's usefulness by demonstrating its breadth of clinical feedback, thereby enhancing its image. It has the potential of increasing trust as it demonstrates the willingness of pathologists to participate in medical audit alongside their clinical colleagues. It also encourages a more responsive, problem-oriented autopsy and report by focusing attention on specific clinical questions. As a result of all these advantages, we hope this type of program may help restore some vitality to the autopsy and help stem its undeserved reputation as irrelevant. Acknowledgments. The authors thank Drs. Andrew Saladino and Howard Rawnsley for review of the manuscript and helpful suggestions, and Edith Williams for expert typographic and secretarial assistance. References 1. Anderson RE: The autopsy as an instrument of quality assessment: Classification of premortem and postmortem diagnostic discrepancies. Arch Pathol Lab Med 1984; 108: Asnaes S, Frederiksen V, Fenger C: The value of the hospital autopsy. A study of causes and modes of death estimated before and after autopsy. 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JAMA 1983;250: Thurlbeck W: Accuracy of clinical diagnosis in a Canadian teaching hospital. Can Med Assoc J 1981; 125: Wilson RR: In defense of the autopsy. JAMA 1966; 196: Woodruff KH: The relevance of autopsy examination (letter). Hum Pathol 1982; 13:605