attempts to use the scientific method, and applies both positive and negative incentives for change and improvement in performance.


This review and comparison of the traditional and continuous improvement models for quality assurance sets forth concepts and terms used throughout the report. The two models are also judged against 15 attributes the committee identified as desirable for a quality assurance program.

The lesson is that no single approach or conceptual framework is likely either to suit our purposes or to meet the criteria we have identified for an effective quality assurance program. The study committee had widely divergent views on the benefits of the continuous improvement model given the limited knowledge about its application to clinical problems and settings of care outside the hospital; the lack of consensus on the committee about a “best” approach to quality assurance and quality improvement is a microcosm of the larger debate in the health care community on concepts and models of quality assurance.

The continuous improvement model has already had a considerable impact on the quality assurance field. The committee’s debate underscored the need for flexibility and innovation in the Medicare quality assurance program over the coming decade. Caution was taken to avoid locking the Medicare program into, on the one hand, an older, familiar conceptual model or, on the other, a very appealing yet unproven new system. Rather, we draw on all the elements of these approaches to fashion a program for quality assurance in Medicare (Chapter 12) that we believe will foster improvement in the quality of health care as it was defined in Chapter 1.



The quality-of-care literature is enormous. The few historical overviews of quality assurance programs include: Egdahl, 1973; Williamson, 1977, 1988; Williams and Brook, 1978; Lohr and Brook, 1984; and Donabedian, 1989.


The mechanics of quality assurance may be tailored to specific categories of quality problems or to given settings, such as efforts designed to address problems of underuse of outpatient or inpatient care in a health maintenance organization (HMO) or those intended to improve nursing aide care in a home health agency. Chapters 7, 8, and 9 discuss these points at greater length; examples of methods are found in Volume II, Chapter 6.


The term outliers typically refers to clinicians or institutions that render seriously substandard or unorthodox care. A rough rule of thumb might be that it refers to the worst 1 percent or 5 percent of providers on a quality measure, although it can be defined in strictly statistical terms.

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