A personal tribute to Kerr L. White, M.D., my career mentor, colleague, and friend

Health Services Research, April, 1997 by John W. Williamson

It is an honor to provide a brief commentary on Kerr White's 1995 essay, "The Ecology of Medical Care: Origins and Implications for Population-Based Healthcare Research" (White 1995), giving emphasis to the impact Dr. White has had on my personal thinking and career development.

Dr. White's 1995 "ecology" essay derives from his 1961 classic contribution to our knowledge of health services, entitled, "The Ecology of Medical Care," (White, Williams, and Greenberg 1961), and its lucid and more refined 1973 follow-up publication, "Life and Death and Medicine" (white 1973). In my judgment, the fundamental message of these articles is far more than an admittedly essential emphasis on the tools and foci of scholarly inquiry related to healthcare. Kerr's basic concern is with the basic responsibility of society to allocate healthcare resources in the most meaningful and appropriate manner to improve the quality of healthcare outcomes for providers and consumers, both individually and collectively. As he so aptly states in his 1961 treatise: "In essence, it [medical care research] is concerned with medicine as a social institution." Kerr White's concern has been, and always will be, people themselves. Over the many years of our association, he has often stated that health statistics are merely people with the tears wiped off. I was delighted to see that in his 1995 essay, he has somewhat refocused his ecology theme to the final end of improving healthcare quality for population groups, based on evidence and methods derived from the healthcare research laboratory.

Kerr White's fundamental concern with improving the health and welfare of large populations became an organizing framework for my own career evolution. The first, and overriding focus of my own contributions was what has since become known as the field of quality improvement (White 1995). This interest was directly encouraged and supported by my association with Kerr and encompassed a communality of values, concepts, and research emphases.

COMMENTARY ON KERR WHITE'S 1995 "ECOLOGY" ESSAY

Kerr White's paper entitled: "The Ecology of Medical Care: Origins and Implications for Population-Based Healthcare Research," was written for the dedication of the Kerr L. White Institute for Health Services Research. This essay has three major sections: (1) The importance of population-based research; (2) a historic review of pioneers who elucidated the quantitative issues of such research; and (3) the concepts, tools, and resources required for the future of "quality management" research. I will discuss each of these themes conceptually, in the context of the evolution of my own career development.

His first major theme concerns the importance of population-based research. In the opening section of his 1995 "ecology" essay, Kerr points out the importance of population-based research as the foundation for the management of healthcare quality. He reviews three classes of population denominators that hearken back to his 1961 "ecology" article, namely: (1) the geopolitical denominator for understanding healthcare needs of the total population, including those either not needing or not seeking care; (2) the healthcare system denominator of those enrolled in a formal care program; and (3) "special-focus" denominators of subsets of the healthcare system. As depicted in his 1995 ecology article, Kerr's first population denominator (geopolitical) is represented by the first and second squares of Figure 1 in his 1961 article. However, at the time of his original article, for reasons of data availability, he restricted his total group to "Adults 15 (or 16) Years of Age and Over."(1)

The second population denominator (healthcare system) in Kerr's 1995 article represents the third square of his 1961 article, roughly approximating the proportion of the sick population who actually seek care. (Note that in this case, he restricts this group to those seeking help from a physician, as opposed to any care source, as is now implied in his 1995 "ecology" article. Finally, Kerr's 1995 third population denominator (specific care sources) represents all of the last three boxes of his 1961 depiction. (Note that these 1991 nested boxes do not necessarily represent subsets of the next-larger box within which they are shown, a fact that Kerr partially corrects in his 1973 "Life and Death and Medicine" article (White 1973), where he drops the "referred to another physician" group, making each of his 1973 cubes more logically a subset of the next-larger cube in which they are depicted. Thus, it is fascinating to note the evolution of Kerr's own thinking from 1961 to 1995. His later "ecology" essay is more basic, and at the same time more precise, in that he now allows for multiple denominator groups for population studies, depending on the exact topic being studied. This occurs without detracting in any way from the genius of his original 1961 thesis that has slowly, but surely, influenced the direction of the entire field of health services research in this country since that time.