National Academies Press: OpenBook

Modern Methods of Clinical Investigation (1990)

Chapter: 4. What is Outcomes Research?

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Suggested Citation:"4. What is Outcomes Research?." Institute of Medicine. 1990. Modern Methods of Clinical Investigation. Washington, DC: The National Academies Press. doi: 10.17226/1550.
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Suggested Citation:"4. What is Outcomes Research?." Institute of Medicine. 1990. Modern Methods of Clinical Investigation. Washington, DC: The National Academies Press. doi: 10.17226/1550.
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Suggested Citation:"4. What is Outcomes Research?." Institute of Medicine. 1990. Modern Methods of Clinical Investigation. Washington, DC: The National Academies Press. doi: 10.17226/1550.
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Suggested Citation:"4. What is Outcomes Research?." Institute of Medicine. 1990. Modern Methods of Clinical Investigation. Washington, DC: The National Academies Press. doi: 10.17226/1550.
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Suggested Citation:"4. What is Outcomes Research?." Institute of Medicine. 1990. Modern Methods of Clinical Investigation. Washington, DC: The National Academies Press. doi: 10.17226/1550.
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Suggested Citation:"4. What is Outcomes Research?." Institute of Medicine. 1990. Modern Methods of Clinical Investigation. Washington, DC: The National Academies Press. doi: 10.17226/1550.
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Suggested Citation:"4. What is Outcomes Research?." Institute of Medicine. 1990. Modern Methods of Clinical Investigation. Washington, DC: The National Academies Press. doi: 10.17226/1550.
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Suggested Citation:"4. What is Outcomes Research?." Institute of Medicine. 1990. Modern Methods of Clinical Investigation. Washington, DC: The National Academies Press. doi: 10.17226/1550.
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Suggested Citation:"4. What is Outcomes Research?." Institute of Medicine. 1990. Modern Methods of Clinical Investigation. Washington, DC: The National Academies Press. doi: 10.17226/1550.
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Suggested Citation:"4. What is Outcomes Research?." Institute of Medicine. 1990. Modern Methods of Clinical Investigation. Washington, DC: The National Academies Press. doi: 10.17226/1550.
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Suggested Citation:"4. What is Outcomes Research?." Institute of Medicine. 1990. Modern Methods of Clinical Investigation. Washington, DC: The National Academies Press. doi: 10.17226/1550.
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Suggested Citation:"4. What is Outcomes Research?." Institute of Medicine. 1990. Modern Methods of Clinical Investigation. Washington, DC: The National Academies Press. doi: 10.17226/1550.
×
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Suggested Citation:"4. What is Outcomes Research?." Institute of Medicine. 1990. Modern Methods of Clinical Investigation. Washington, DC: The National Academies Press. doi: 10.17226/1550.
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Suggested Citation:"4. What is Outcomes Research?." Institute of Medicine. 1990. Modern Methods of Clinical Investigation. Washington, DC: The National Academies Press. doi: 10.17226/1550.
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4 What Is Outcomes Research? JOHN E. WENNBERG In "The Structure of Scientific Revolutions" Thomas Kuhn suggests that sci- ence is what scientists do. I want to take my cue from him and will discuss what our research team is doing that we call outcomes research. I then will return to Kuhn to make some more general observations about the status of out- comes research and the emergence of evaluative clinical sciences as a response to medicine's current predicament. WHICH RATE IS RIGHT? For some time, our research group has been conducting a series of investiga- tions of the outcomes of treatment for benign prostatic hyperplasia (BPH). These investigations are part of an effort to come to terms with the puzzling geographic variations in rates of use of medical care. By the mid 1970s, I had become convinced that these variations exist primarily because of differences in physician practice style, and that a resolution of the puzzle required direct inquiry into the effect on outcome of the various opinions or clinical theories underlying these practice styles (1~. By the early 1980s, Dan Hanley, David Soule, and Alice Russell had organized leading physicians in Maine into study groups to investigate the variations (2~. These study groups became the focus of an alliance between practicing physicians and researchers that made many of our studies possible. Of these studies, the assessments of alternative treatments for BPH have become the most widely known, and it is fair to say that it is in the groping for solutions to the problems associated with BPH that our understanding of out- comes research has developed the furthest (3-7~. The BPH study group, orga- 33

34 JOHN E. WENNBERG nized in 1982 by Robert Timothy, consists largely of practicing urologists. Our BPH assessment team consists of research urologists, medical care epidemiolo- gists, decision analysts, statisticians, psychometricians, computer scientists, and experts In interactive videodisc technology (see Table 4.11. At issue is the treatment of prostatism or obstruction of the urinary tract due to benign hyperplasia of the prostate gland. BPH is a very common condition, affecting the majority of men by the seventh or eighth decade of life. One com- TABLE 4.1 Members of the BPH Assessment Team Discipline Members Location Biostatistics Klim McPherson Oxford, U.K. Clinical Decision Analysis Michael J. Barry Albert G. Mulley Boston, MA Boston, MA Computer Science/Interactive Eric Baumgartner Hanover, NH Videodisc Technology J. Robert Beck Hanover, NH Joseph V. Henderson Washington, DC Harold C. Lyon, Jr. Hanover, NH Barbara Sasso Hanover, NH Coralea Wennberg Hanover, NH Medical Care Epidemiology/ Nicolas Black London, U.K. Claims Data Studies Thomas A. Bubolz Hanover, NH Marsha M. Cohen Manitoba, Canada Elliott S. Fisher Hanover, NH E. Robert Greenberg Hanover, NH David J. Malenka Hanover, NH Dale McLerran Hanover, NH Aviva Ron Tel Aviv, Israel Leslie L. Roos Manitoba, Canada Noralou P. Roos Manitoba, Canada John H. Wasson Hanover, NH John E. Wennberg Hanover, NH Medical Ethics Charles Culver Hanover, NH Psychometrics/ Tavs Folmer Anderson Copenhagen, Survey Research Denmark Floyd J. Fowler Boston, MA Urology Reginald Bruskewitz Madison, WI Abraham Cockett Rochester, NY John A. Heaney Hanover, NH H. Logan Holtgrewe Annapolis, MD Ernest Ramsey Manitoba, Canada Stuart M. Selikowitz White River Jet., VT Robert P. Timothy Portland, ME

WHAT IS OUTCOMES RESEARCH? 35 man treatment for BPH is an operation, a prostatectomy. The rate of prostatec- tomy varies strikingly among neighboring communities. In some places about 10 percent of men undergo this operation by age 85, while in other communities the proportion can be as high as 50 percent. In 1987, some 340,000 prostatec- tomies were performed for BPH at a cost of roughly $4 billion. Another com- mon treatment for BPH is watchful waiting. In communities with low rates of prostatectomy, proportionately more men with BPH are treated by this alterna- tive strategy. Clinical practice in these communities emphasizes the viewpoint that prostatectomy is an elective procedure, reserved for those with truly bur- densome symptoms. The assessment of BPH started with a discussion between the researchers and the members of the study group, who represented many geographic areas in Maine with considerable variations in rates of surgery. This discussion focused on establishing the different points of view or clinical theories behind these geo- graphic variations. Together with a review of the scientific papers published on BPH, it uncovered an important and unsettled controversy concerning the indi- cations for the operation. Many physicians hold the theory that prostatectomy should be performed early in the course of BPH as a preventive measure. They reason that if the operation is delayed, the patient will be older and at higher risk when it finally becomes unavoidable; if the operation is delayed, life expectancy is reduced. According to this theory, watchful waiting is not a rea- sonable option for most patients. Other physicians argue that the need for the operation is not inevitable, that it does not improve life expectancy for most patients and that the primary reason for surgery is relief of symptoms and improvement in the quality of life. According to this theory, watchful waiting is a reasonable option for patients who prefer to live with their symptoms to avoid the risks of surgery (4-6~. The assessment team tested this conflict in theory and reached several con- clusions. Evidence from the literature and from claims data demonstrated that the preventive theory was incorrect: an operation in patients with uncomplicat- ed BPH which most patients have very likely causes a slight decrease in life expectancy. The assessment thus confirmed the opinion of those physicians who felt the operation was justified because it reduces symptoms and improves the quality of life. Interview studies with patients before surgery and at three, six, and twelve months after surgery documented changes in symptom and func- tional status related to the operation. These studies showed that the value of the operation for most patients is that it is better than watchful waiting for reducing symptoms and improving quality of life. However, these gains are available only to patients willing to take the risks of the operation, which include death, failure to improve symptoms, impotence, and incontinence. The decision to undergo the operation is thus highly dependent on patients' preferences for out- comes and their attitudes toward risk. This substantial clarification of theory occurred without a prospective clini-

36 JOHN E. WENNBERG cat trial; the steps undertaken and the disciplines involved are listed in Table 4.2. Note the emphasis on study groups with physicians to learn about their the- ories of treatment, and focus groups with patients to learn about the expecta- tions and outcomes that matter to them. The literature review and the claims data provided enough information to define the actuarial expectations for the operated and unoperated patient (without chronic retention) and to test the pre- ventive theory of early prostatectomy. We had to depend on the placebo arm of a few drug trials and a scant series of four studies of BPH patients treated with watchful waiting for estimates of the natural history of symptoms and the fre- quency of crossover to operation. We found no satisfactory information on symptom relief after surgery in the literature, so we conducted our own study. The results provide convincing evidence that the operation is much more effec- tive than watchful waiting as a treatment for BPH symptoms. Thus, there is no dispute about the "main effect" superiority of surgery over watchful waiting. Decision analysis, used to test the preventive theory, also demonstrates that the decision to undergo the operation depends on patient attitudes toward impo- tence, incontinence, and the operative mortality rate. The subjective factors of risk aversion and personal tolerance for disease symptoms thus emerge as important elements of rational choice. The BPH assessment had immediate practical value for clinical decision making because it clarified controversies, established correct theory, and pro- viding detailed probability estimates, some of which had not been previously studied. The effect of practice style on variation in prostatectomy rates was traced to an incorrect belief in the preventive theory of early prostatectomy and TABLE 4.2 Synopsis of BPH assessment: Prostatectomy versus watchful waiting Steps Used in the BPH Assessment Evaluative Clinical Sciences: Methods/Disciplines Identify treatment theories and evaluate Identify and develop measures of relevant outcomes from patient's and from physician's points of view Undertake non-experimental studies to estimate (missing) outcomes probabilities Integrate information from all sources to test preventive theory and evaluate importance of patient utilities Structured review of the literature; meta-analysis; focus groups with . . . physicians Study focus groups; algorithms using claims data; patient interview instruments Claims data studies; interview studies of surgery patients Decision analysis used as "thought experiment"

WHAT IS OUTCOMES RESEARCH? 37 failure to take patient preferences into account when recommending prostatecto- my. The remedy for unwanted practice-style variations, we concluded, requires the active engagement of the patient in the decision. It requires informing physicians and patients of the risks and benefits of prostatectomy and its alter- native, watchful waiting. ENGAGING PATIENTS IN THE DECISION PROCESS We are seeking new ways to engage patients in the decision process and to make our detailed probability estimates available to patients and physicians in "real time" for use in clinical decision making. To do this, we have developed a "BPH Shared Medical Decision Making Procedure" based on interactive videodisc technology. This interactive program can be used in the physician's office after standardized information on health status and physical condition is entered into the data base. The patient is asked to provide information about symptoms, functional status, and the strength of his feelings about them. This information allows us to identify the relevant prognostic subgroup to which the patient belongs so that a patient can be given the best available estimate. The patient is then shown an audiovisual narration depicting the available choices, their possible outcomes, and associated probabilities. Interviews with two physician-patients (one who chose watchful waiting and the other prostatec- tomy) convey to the patient that there is indeed a choice; if physicians choose differently, so can their patients. Other interviews are testimonies about the principal outcomes, including an example of a complication associated with either choice. The interactive computer feature of the Shared Medical Decision Making Procedure means that information on the probabilities for outcomes is specific to the patient's subgroup, according to symptom severity and age. The patient can also exercise options to learn more about issues of particular con- cern and can review the presentation. At the end, the patient is given a printed synopsis to discuss with family and physician. The physician then helps the patient make a decision. The BPH assessment conducted so far does clarify controversies in basic clinical theory and provides better estimates than previously available for symp- tom status. But important uncertainties remain about some probabilities that are important for patients with BPH who are trying to evaluate risk. The attributable postoperative (30-day) risk of death for prostatectomy remains unclear. For patients who underwent surgery, the sample on which estimates of symptom improvement and incontinence are based is small (about 400), so the standard deviations are sometimes large. For untreated patients, the situation is even less satisfactory. Given a watchful waiting situation, we were unable to obtain an accurate estimate of the chance of a second episode of acute retention. This information is important for helping patients who present with acute reten- tion to decide on treatment. The characteristics of the watchful waiting sub-

38 JOHN E. WENNBERG group at risk for progression to chronic obstruction (with the potential for blad- der decompensation) are also unclear. The interactive videodisc program can help fill in these missing probability estimates because it is also a tool for outcomes research. At the first viewing, the patient can be enrolled in a prospective study of outcomes based on his choice of treatment a cohort study that we call a preference trial. For out- comes research, the patient must return later (e.g., after 3, 6, or 24 months), regardless of type of treatment, at which point additional information about health and satisfaction with choice is entered into the data base. These data, accumulated over time and for many patients, can be used by researchers to update the information presented to future patients. In this way, the device par- ticipates in its own update and helps improve the scientific basis of medicine. We also plan research protocols to improve our understanding of the "framing" effects of our data displays and to learn more about helping patients make deci- sions consistent with their preferences. An important objective of these research protocols is to learn more about, and improve the role of, the physician as counselor and "cognitive" advisor to patients. EXTENDING ASSESSMENT TO ALL RELEVANT TREATMENT THEORIES In the course of our work we have encountered a number of other theories or controversies concerning the treatment of BPH. One is an "old" theory that the transurethral approach to prostatectomy has better outcomes than the open prostatectomy. Another is that prazosin and other alpha-blockage drugs used to treat hypertension are useful treatments for symptoms of BPH. We also found new techniques for treating BPH based on balloon dilation and identified two promising drugs undergoing FDA evaluation, a less invasive operative tech- nique (prostatotomy), and a microwave diathermy treatment which is thought to relieve symptoms by reducing prostate size through the scarring of tissue. As our thinking about our role has evolved, we have come to see the advantages of having the assessment team include all alternative treatments, the old as well as the emerging. We therefore want to address the evaluative challenges each of these theories presents. With the exception of the relative effectiveness of transurethral prostatecto- my (TURP) versus open prostatectomy (an issue I will address below), these theories are quite new and few data exist on which to base an evaluation. The need for prospective evaluation thus arises. There is a debate within our group concerning approaches to prospective evaluation. We began with the orthodox view that a double-blind, placebo-controlled randomized clinical trial (RCT) is the optimal strategy for establishing the probability for outcomes of alternative treatments, but some of us are no longer sure that this is always the case. Our debate is not about the recognized difficulties of RCTs, such as the issue of

WHAT IS OUTCOMES RESEARCH? 39 placebo controls and patient blinding when surgery is involved, the problems of costs, logistics, and changing technology that can befuddle studies where end- points require many years of follow-up, or the problem posed by rare diseases where cases are few and far between. Our conclusions about the importance of patient preferences for rational decision making, at least in the treatment of BPH, raise questions about the role of randomization itself. The first question concerns the ethical requirements for shared decision mak- ing and the legal requirements for informed consent. When the outcomes of alternative treatments for a given condition are asymmetric in some significant dimension say, known differences in the risk of death patient preferences with regard to what is known about these risks should influence treatment assignments. This is a strong challenge for the planning of further studies of watchful waiting versus TURP, where the uncertainty is not even about the "main treatment effect" probabilities, but about prognosis in certain subgroups on the watchful waiting arm. When informed about this uncertainty, few patients who want to share responsibility for decision making are indifferent to randomization. In this case, the most efficient and ethical way to obtain the missing probabilities and characterize patient subgroups may well be a prefer- ence trial the systematic follow-up of patient cohorts where treatment assign- ments are made according to informed patient choice rather than by randomiza- tion. A similar problem may exist in the evaluation of drugs such as prazosin. In this situation, the "main effect" probabilities concerning symptom relief are unknown and the rationale for randomization seems more compelling. However, Phase I safety studies (and the vast experience gained with prazosin in its use as an antihypertensive drug) show that mortality, over the short term at least, is lower than that following surgery, and that the drug does not cause incontinence. Again, when informed, few patients who want to share responsi- bility for decision making accept randomization. The unwillingness of informed patients to accept randomization may not be the main point, however. The more important issue may be which approach provides the more useful information. To understand this, we need to know a good deal more about the confounding effects of study design on probability estimates, particularly for soft outcomes. A pragmatic view is that the informa- tion generated by clinical trials is useful only to the extent that it helps decide choice of treatment. When choice is delegated to the physician, the physician alone makes the connection between the evidence from clinical trials and the patient. In this case, the probabilities obtained under randomized designs that ignored or minimized the importance of patient preferences may be the best estimates for decisions. Under the shared decision making paradigm, however, it is not self-evident that classic RCTs provide the most accurate information. Imagine a clinical trial of prazosin in which patients with BPH are randomly assigned to a preference trial or an RCT. Patient characteristics (co-morbidities,

40 JOHN E. WENNBERG symptom status, demographics, etc.) are obtained before patients are given information about their choice. A modified version of the Shared Medical Decision Making Procedure (described above) is needed to present information uniformly to patients in all cooperating centers. On one arm of the trial, patients are offered surgery, watchful waiting, or the opportunity to participate in a dou- ble-blind, placebo-controlled randomized clinical trial of prazosin, based on the full disclosure of information which the ethics of shared patient decision mak- ing requires. On the other arm, they are offered a preference trial the opportu- nity to elect surgery, watchful waiting, or prazosin, based on the same disclo- sure about what is known (and not known) about the effect of the drug. Patients who want additional information or advice before deciding on treatment are counseled by physicians operating under standard protocols who do not admin- ister treatments. Follow-up to determine outcomes is by observers who are blinded as to treatment received. I have diagrammed such a trial in Figure 4.1. The trial would explore a number of interesting problems. Would more patients elect the drug if they knew they would get it than would elect the dou- ble-blind trial? Would the subgroup of patients electing the double-blind trial fairly represent those who elect prazosin with the knowledge that they will get their choice of treatment? That is, would the probabilities for symptom reduc- tion and other outcomes estimated in the double-blind trial be the same as those estimated in the preference trial? It seems to me they would not. Patients who agree to randomization after a fair presentation of the treatment dilemmas are very likely different from those who choose prazosin. Moreover, I suspect that the outcomes associated with freely chosen treatments will be more positive. SMDP-RCT Surgery N__/ C~ Placebo \ Watchful Waiting Surgery Prazosin \ Watchful Waiting FIGURE 4.1 Proposed trial of a trial: Preference design versus double-blind randomized design.

WHAT IS OUTCOMES RESEARCH? 41 The preference effect I am postulating is the common-sense notion that a treat- ment chosen by patients who believe it will help them is more likely to have a positive effect than randomly assigned treatments. Studies of the effect of patient compliance in double-blinded RCTs provide some strong hints about the importance of the preference effect. David Sackett has found five documented instances where patients who comply with treatment regimens have substantially better outcomes, including survival, than noncom- pliant patients, even on the placebo arm of the trial. Which set of probabilities is most relevant to the everyday clinical situation? Under the shared decision making paradigm, the answer seems intuitively clear. The correct probabilities are those based on preference trials, where patients knowingly choose treat- ments on the basis of information about probabilities for the outcomes relevant to them. However, reliance on preference trials makes sense only if we can dis- tinguish therapeutic effects from the effects of preference, placebo, and compli- ance. The trial I have proposed to you, because it also studies patients who choose watchful waiting and provides a complete accounting of choice and out- comes on both major arms of the study, may allow us to disentangle these effects. Under the paradigm of shared decision making, what has been viewed as a distinct boundary between clinical research and everyday clinical practice promises to become blurred. The tools that help patients make informed choice also are useful for organizing clinical studies. The preference trial approach may prove more acceptable to practicing physicians and increase the possibility for large-scale, cooperative studies. It is somewhat of a scandal that, although prostatectomies have been performed since the beginning of this census and more than 350,000 are now performed annually in the United States, fewer than 400 patients—our series in Maine- have been followed systematically to study the "main effect" outcome, the effect of the operation on symptom status. The information on symptom status and crossover to operation for patients choosing watchful waiting is based on only four studies of a small series of non-operated patients. I believe that many more patients will elect experimental treatments under preference designs than under randomized designs. If this is so, and if we become confident about the limitations and advantages of preference trials, this change will greatly speed the process and reduce the costs of technology assess- ment as well as provide new methods for Phase IV studies. For example, pra- zosin is now used extensively in everyday clinical practice in this country, but in order for its manufacturer to advocate its use for the treatment of BPH it must undergo an extensive series of RCTs. For all this trouble we would know little more than its relative value compared to a placebo; we would know nothing about the probabilities that count in clinical practice, such as its relative effec- tiveness compared to watchful waiting or surgery, and its value when patients freely choose their treatments. My hope is that our assessment team can broad- en the investigation of the relative advantages of preference versus randomized

42 JOHN E. WENNBERG clinical trials across the full spectrum of assessment issues we have encoun- tered, including the merits of balloon dilation, microwave diathermy, and sever- al new drugs. .. . ~ . .. . . . . · · . . we also need to consider the value or ootn trial Designs in resolving another treatment controversy: the relative effectiveness of two surgical approaches to the prostate the transurethral or the open prostatectomy. Over the past three decades, BURP has virtually replaced the older open operative techniques. This replacement, which occurred without prospective clinical trials, reflects the belief that TURP is a safer, less invasive operation that is effective in the long term. Since the administrative data bases available to our team extend back to the 1960s, we have compared the outcomes of these two operations over a con- siderable span of time. The results indicate that the open operation may be more effective. Patients with an open operation have significantly lower rates for stricture and reoperation, suggesting that the more complete removal of the prostate following the open operation, which is less traumatizing to the urethra, results in better long-term reduction of urinary symptoms. More puzzling and disturbing is the unexplained elevation in risk of death in the years following AMP. In separate studies undertaken in Maine (U.S.A.), Manitoba (Canada), Oxford (U.K.), and Denmark, we find the risk of death is significantly higher in the five years following operation. In view of our concern that the higher mortality following BURP may occur because those patients are sicker than those undergoing open prostatectomy, we abstracted data on severity of illness from the medical charts at a large universi- ty hospital. Even after adjustment, however, the 45 percent higher mortality rate following TURP was unchanged. The consistency of the findings, and our failure to explain them on the basis of data available in medical charts, led us to conclude that differences in co-morbidity do not explain the effect and that a prospective study is needed to evaluate this problem. Over the past several months, our assessment team has been in contact with urologists in various countries, including the leadership of the American Urological Association (AUA). We are extremely pleased that AUA has urged its members to participate in a large-scale clinical trial. The clinical trial being planned will not concentrate solely on the open versus TURP controversy. Since the available data suggest that BURP does harm, we have reasoned that this harm, if a true effect, will reveal itself no matter what the comparison group. The clinical trial thus provides the opportunity for direct comparison of new technologies balloon dilation, microwave diathermy, and the new drugs with surgery and watchful waiting. We hope that the clinical trial will provide the essential information on the outcome of all new treatment theories relevant to treatment of BPH. We emphasize randomization in this situation for several reasons. It would be unwise to base the primary test of open prostatectomies versus BURP on a preference trial, because the necessary methodologic work to understand the

WHAT IS OUTCOMES RESEARCH? limits and advantages of preference trials has not been done. The controversy here is about the role of patient risk factors as the confounding variables respon- sible for higher mortality rates following TURP. Well-conducted and large- scale randomized clinical trials give assurance that patient differences do not confound treatment effects. Moreover, it is ethical to randomize if the patient will accept randomization: our assessment team is uncertain whether the effect is caused by BURP or by differences in patient characteristics that we could not detect using the retrospective data available to us. The great majority of physi- cians do not believe the effect is due to the operation. As a secondary strategy, however, there may be an advantage if practices not able to participate in randomized clinical trials (because open operations are not available) participate in preference trials. Under the hypothesis that patient dif- ferences do not account for the observed differences in mortality following TURP versus open prostatectomy, TURP appears to reduce life expectancy. The effect should therefore be observable in a preference trial where BURP is compared to a control population undergoing watchful waiting or some other alternative. An advantage of such preference trials would be the speed with which additional information on this important problem could be expected to emerge. THE EVALUATIVE CLINICAL SCIENCES AND THE FUTURE OF MEDICINE I now turn to the more speculative task of attempting to relate outcomes research to current struggles about the future of medicine. Again, Thomas Kuhn provides an appropriate context. He teaches that when the rules and pro- cedures of a science no longer deal effectively with anomalies of theory or experimental evidence, a new science emerges. Problems are stated in new ways; new disciplines establish themselves; and new techniques provide solu- tions not previously possible. I believe that the emergence of the evaluative clinical sciences, as a set of disciplines distinct from biomedical science, is a response to the increasingly obvious anomalies of the model on which clinical and health care policy decision making has been based. That model is the more or less passive delegation of decision making to physicians who, to use Kenneth Arrow's term, act as rational agents for patients and society to assure that health resources are distributed optimally. The rational agency theory depends on two key assumptions about physicians. First, that by virtue of the strength of biomedical science and their own clinical experience, physicians know the prognosis for the various treatments available to a patient with a given condi- tion. Second, that physicians choose treatments that maximize patient utility, and that they can wisely choose the right treatment for the individual patient, disentangling their own preferences to deal with the problem of interpersonal differences in utility. This requires successful negotiation of E. B. White's 43

44 JOHN E. WENNBERG observation that one man's meat is another man's poison, in order to make vicarious judgments about which treatment has the highest expected value for any patient. The anomalies of rational agency theory are now evident to a widening audi- ence. It is increasingly apparent that the large investment in biomedical science has not resulted in a consensus among physicians on the correct way to practice medicine, nor has it resulted in orderly assessment of treatment theories. Quite the contrary, biomedical science, by virtue of its prodigious success, appears to have increased uncertainty and practice-style variations by offering an ever increasing supply of new technology and new biomedical ideas. This is behind the shocking variations in costs and utilization between Boston and New Haven, where the scientific credentials of local medicine are state of the art. It is also increasingly apparent that patients want to participate in determining their own medical fates and that physicians have neither the information nor the decision mak- ing skills to always choose the treatment that will maximize patient utility. These challenges, emerging at a time of runaway costs, growing consumerism, and concern about patients' rights, have effectively dissolved long held assump- tions about the efficacy, the ethical sufficiency, and the legal basis of the dele- gated decision making model. The breakdown is apparent in two ways. On the microscale, the impact is felt in the changing doctor-patient relationship, where physicians face an increasingly assertive and sometimes litigious clientele. The passive trust that manifested itself in the patient's willingness to delegate decision making to the physician and accept what happens as fate has receded. More and more, patients demand active involvement in the decisions that determine their medi- cal futures—even when this participation forces exposure to the reality that physicians do not know all the facts. This is not to say that patients must distrust their physicians or that a signifi- cant minority now do. But it does identify a new relationship based on an active patient role where decision making is shared, not delegated. In this new role, the challenge to the physician is to learn how to function in what some have called the cognitive role as an advisor or counselor who understands the need to act on imperfect information and who helps individual patients under- stand their own preferences, given the dilemmas the physician and the patient face together. It is perhaps on the macroscale of socioeconomics, of reaction to runaway costs, that the breakdown is most acutely felt by physicians. Understanding the flaws in the rational agency theory helps explain runaway costs. Demand is not controlled by professional consensus on "correct practice"; the supply of man- power and technologies, medical theory and practice style, are in dynamic equi- librium. Technologic possibilities, the numbers of physicians practicing medicine, and the costs of care are now such that many politicians, government officials, corporate officers, and labor leaders perceive further growth in the

WHATIS OUTCOMES RESEARCH? 45 health care sector as a threat to other societal priorities. More and more, gov- ernment and private corporations are intruding into the doctor-patient relation- ship in their attempts to control demand. The emergence of the evaluative clinical sciences and outcomes research is a response to the intellectual crisis created by the demise of the rational agency theory and the loss of faith that biomedical science, through its own internal logic, assures effective medical practice. It is an effort to provide the method- ologies, strategies, and knowledge base needed to support a new model for clin- ical decision making, one that Albert Mulley has suggested be called the shared clinical decision making model. The model preserves the notion that consumer preferences and knowledge about outcomes should serve as the regulator of patient behavior and of aggregate demand. But it also recognizes the inherent limits in the ability of physicians to determine vicariously what treatments patients value most. The evaluative clinical sciences seek to make possible bet- ter clinical decisions based on a fuller understanding of outcome probabilities, and active participation of patients in selecting treatments. The outcomes research agenda thus seeks to do something quite new. It focuses on the systematic evaluation of all of the outcomes that are relevant to patients mortality, morbidity, complications, symptom reduction, and func- tional status improvement as well as the physiologic or biochemical indicators which have perhaps too often been assumed to be valid surrogates for patient well-being. It focuses on the systematic evaluation of all (reasonably held) the- ories and alternative practice styles that are relevant to a particular condition or illness. It emphasizes assessment teams, organized around specific conditions with ongoing responsibility for evaluating all treatment options, old and new. The outcomes research agenda thus removes the "double standard of truth" that has characterized previous evaluation approaches. These approaches have main- ly concentrated on new drug evaluations, while ignoring evaluations of the use of approved drugs in novel ways, of surgical operations and other procedures such as balloon angioplasty, or of the use of hospitals compared to ambulatory care settings for chronic and acute conditions. Outcomes research focuses on the development of methods and strategies for conveying information in ways that activate the patient as a partner in decision making. The research agenda includes a broad emphasis on learning to help patients make decisions consis- tent with their own preferences. The outcomes research agenda focuses on new strategies and methods for making inferences to improve the validity and efficiency of evaluative research. Emphasis is placed on developing a proper balance between non-experimental and experimental methods for making inferences, and exploring the available options. Decision analysis is emphasized as a tool for organizing thinking, for conducting "thought experiments" to evaluate whether a particular treatment controversy is about the probabilities for outcomes, or whether it is really about the value of outcomes for patients. And, because the Shared Medical Decision

46 JOHN E. WENNBERG Making model emphasizes the importance of patient preferences, He agenda accentuates Be need to learn He advantages and limitations of basing treatment assignments in prospective clinical research protocols on patient preference rather than on randomization. REFERENCES 1. Wennberg JE, Bunker JP, Barnes B. The need for assessing the outcome of com- mon medical practices. Annual Review of Public Health 1980; 1 :277-295. 2. American Medical Association. Confronting Regional Variations: The Maine Approach. Chicago: American Medical Association, 1986. 3. Wennberg JE, Freeman JL, Shelton RM, Bubolz TA. Hospital use and mortality among Medicare beneficiaries in Boston and New Haven. New England Journal of Medicine 1989;321:1168-1173. 4. Wennberg JE, Mulley AG, Hanley D et al. An assessment of prostatectomy for benign urinary tract obstruction. Journal of the American Medical Association 1988;259:3027-3030. 5. Fowler FJ, Wennberg JE, Timothy RP et al. Symptom status and quality of life fol- lowing prostatectomy. Journal of the American Medical Association 1988;259:3018-3022. 6. Barry MJ, Mulley AG, Fowler FJ, Wennberg JE. Watchful waiting versus immedi- ate transurethral resection for symptomatic prostatism. Journal of the American Medical Association 1988;259:301~3017. 7. Wennberg J. Roos N. Sola L, Schori A, Jaffe R. Use of claims data systems to eval- uate health care outcomes: Mortality and re-operation following prostatectomy. Journal of the American Medical Association 1987;257:933-936.

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The very rapid pace of advances in biomedical research promises us a wide range of new drugs, medical devices, and clinical procedures. The extent to which these discoveries will benefit the public, however, depends in large part on the methods we choose for developing and testing them.

Modern Methods of Clinical Investigation focuses on strategies for clinical evaluation and their role in uncovering the actual benefits and risks of medical innovation.

Essays explore differences in our current systems for evaluating drugs, medical devices, and clinical procedures; health insurance databases as a tool for assessing treatment outcomes; the role of the medical profession, the Food and Drug Administration, and industry in stimulating the use of evaluative methods; and more.

This book will be of special interest to policymakers, regulators, executives in the medical industry, clinical researchers, and physicians.

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