of information on malpractice litigation. Currently, dissemination of information on malpractice compensation is limited to information on court awards, which like any other court record is public. The information is published sporadically in costly private newsletters that cover metropolitan areas. The 1986 act requires HHS to make physician-identified information collected in the national data bank available to health care entities and licensing boards. Hospitals are required to obtain the information from HHS, and will be presumed to have the information in any medical malpractice action. Information in the data bank will not be available to individuals. Given the problems of using malpractice compensation as an indicator of the quality of care, publicizing such information to consumers requires further examination.

Combinations of Indicators

A centralized system that includes information on formal disciplinary actions taken by State medical boards, sanctions imposed by HHS upon recommendation of PROS, malpractice compensation, and information on other disciplinary actions taken by medical entities could help to identify recurring problems in the care provided by physicians and perhaps improve the validity of each of the actions as an indicator of quality. Shared information could improve the level of decisionmaking by all concerned bodies. If different, independent bodies censure a physician, the probability that the physician is providing substandard care increases.

A combination of indicators might be a more valid indicator of substandard care than a single indicator. The information could assist in improving future care by making it more difficult than it is now for physicians who have been demonstrated to provide substandard care to continue to practice. However, extreme caution would be needed in using this particular combination of indicators. As discussed above, the validity of medical malpractice claims and compensation as an indicator of the quality of care is not clear. Recent data from the New York State Department of Health indicate that there is a linkage between multiple malpractice claims and disciplinary actions taken by the State medical board (460). Phy

sicians who have had 6 or more medical malpractice claims made against them are likely to be disciplined by the New York State medical board: the State medical board took disciplinary action against 17 percent of such physicians. Further work is needed, since only 181 physicians were studied. The validity of adverse actions taken by hospitals and professional societies also needs to be examined.

The national data bank mandated by the Health Care Quality Improvement Act of 1986 is unique in that malpractice judgments on individuals can be compared with the type of disciplinary actions taken by State medical boards and the adverse actions taken by hospitals and professional societies. Since PRO/HHS sanctions will not be included, the usefulness of the data bank will be limited. Information on such sanctions does not appear to be widely disseminated. The Omnibus Budget Reconciliation Act of 1986 (Public Law 99509) requires that PROs share, when requested, information related to substandard care with State medical boards and others, but final regulations had not been released by March 1988.

Interest in greater cooperation and sharing of information is seen in the Medicare and Medicaid Patient and Program Protection Act of 1987 (Public Law 110-93). That law strengthens the provisions in the earlier Health Care Quality Improvement Act and requires States to make available to the Secretary of HHS information concerning disciplinary actions taken by State medical boards against a range of health care practitioners. The 1987 law also requires that the Secretary of HHS disseminate information on these actions to State medical licensure boards and to other State and Federal officials.

As noted earlier, information in the data bank mandated by the Health Care Quality Improvement Act will not be available to individuals, and this situation might be reasonable. A prudent course of action in establishing the data bank would be to begin with fairly detailed data but very limited distribution, and then to test the seeming credibility and usefulness of the data as they begin to accumulate for statistical power or actuarial credibility. The data bank will need to be continuously analyzed and revised with continuing experience.

INTRODUCTION

A major approach to assessing a physician's performance, especially since the 1950s, has entailed evaluation of the care provided for specific medical conditions (184,371). This approach has spread widely during the past two decades as researchers and clinicians have refined assessment techniques. Physicians and other medical professionals have increasingly participated in the review of their peers' performance through privately sponsored activities of hospitals, health maintenance organizations, group practices, medical associations, and third-party payers and through publicly funded programs of State and Federal governments.

This chapter examines the reliability, validity, and feasibility of using evaluations of physicians' performance in caring for a particular condition as an indicator of physician quality. Hypertension is used as a case study condition. Elevated blood pressure is one of the most prevalent and costly medical disorders in the U.S. population, and the effective detection and management of hypertension is one of the Nation's chief public health goals (372,662). Since about 30 percent of the U.S. population is hypertensive,1 an evaluation of the methods used to assess care for hyper

'Estimates of the prevalence of hypertension depend on the precise definition of hypertension adopted. On the basis of the outcome findings of large randomized controlled trials, the Joint National Committee on Hypertension has recommended that patients be diagnosed as hypertensive if the average of blood pressure measurements taken on at least three successive occasions is greater than or equal to 140 mmHg systolic over 90 mmHg diastolic (332). This definition represents a stricter standard than the previous one, which involved repeated measurements above 160/95. Some variation in the specific cutoff pressure levels used for patients in the "mild" hypertensive category still exists among clinicians, especially outside the United States (47). Further, some specialists have argued for diagnosing patients with isolated systolic hypertension as well (717). Because elasticity of the major arteries declines with age, the combined prevalence of isolated systolic and diastolic hypertension for persons aged 65 to 74 is estimated at 64 percent overall and 76 percent in blacks.

tension and to provide information on its quality is important in itself. But evaluating care for hypertension may also illustrate a number of key considerations relevant to evaluating care for other conditions. At the same time, evaluation of the quality of care provided by a physician for hypertension might provide some insights into the quality of other aspects of a physician's services. Consequently, this case study provides a vehicle for analyzing many broader issues in evaluating the process of medical care.

The process of medical care for hypertension is outlined in box 7-A and figure 7-1. In borderline as well as more severe cases, hypertension is generally asymptomatic; its diagnosis depends on the use of blood pressure measurements in individuals who may appear well or who may be seeking care for unrelated health problems. In over 90 percent of cases, hypertension cannot be attributed to an identifiable pathologic cause and must be treated on a chronic, lifetime basis. Detection and followup are crucial, because longterm sequellae of uncontrolled hypertension include serious morbidity associated with strokes, renal disease, cardiac dysfunction, and increased risk of premature death (89). The efficacy of therapies designed to reduce blood pressure toward desired levels in significantly reducing the incidence of these complications was demonstrated in Veterans Administration trials in the early 1970s (676,677). The Hypertension Detection and Follow-Up Program, a 5-year randomized clinical trial with over 10,000 participants, found that a systematic "stepped-care" program for treatment to reduce high blood pressure was associated with significantly higher rates of pressure control and 5-year survival than was "usual" management (313).

OTA's selection of care for hypertension for analysis in this report was based in part on the

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