There is a misunderstanding common to all 4 sets of comments. The issue we addressed is how population change will affect future requirements for physician services — that issue, and that issue alone. To that end, we abstracted from (held constant) all other factors that might affect requirements.
One of our principal findings was that “overall requirements for physicians in consequence of population change alone are almost certain to increase by less in the future than in the past”1 (italics in original). We also noted that a variety of factors would affect future requirements, but to investigate the effects of population change with any precision, it is necessary to abstract from these other factors, important as they may be.
Raymond Dawes says we “postulate that because population increases are now lessening, the future need for physicians will increase to a lesser extent than in the past.” However, we did not and would not draw such a conclusion. It would be unwarranted on the sole basis of our analysis of population effects, with utilization rates held constant.
We agree with Chris MacKnight and David Hogan that fee-for-service may not be “the most appropriate way to fund physician services for aging patients with multiple problems.” However, as we noted,1 fee-for-service practices accounted for almost all physician services in Ontario,2 and the data available to us (for 1995/96) on what services were provided to patients of different ages and sexes related to such practices. MacKnight and Hogan also feel that “using historical data to project future needs … implies that the way we do things now is optimal.” Wrong. There is no such implication in our analysis. In our calculations, we simply keep fixed the most recent utilization rates (whatever they are) and allow only population to change.
Charles Low feels that apparent shortages of both family doctors and specialists make our future projections “difficult to evaluate.” Again, what we were projecting was not changes in requirements for physicians from all causes, but changes resulting only from population aging and growth. We make no judgement about what utilization rates should be but take them as they are.
Michael Borrie and associates assert that we underestimated the “provision and need for services for elderly patients” because we failed to give explicit treatment to geriatricians. We dealt with an exhaustive set of 19 categories of physicians, the maximum for which age-sex rates of utilization are available. The underlying patient utilization data were compiled from OHIP records (the only source), as provided by the Canadian Institute for Health Information (CIHI). Geriatrics is included in the CIHI category “internal medicine” (along with 10 other specialties). Given what Borrie and associates recognize as the low numbers of physicians who have been trained in geriatrics, it should be clear that any separate treatment would have had only a negligible effect on the overall projection results.
Through our analysis we found that demographic effects on overall physician requirements are likely to be smaller than might have been supposed in light of popular discussion of the “aging crisis.” A helpful response to that finding would be something like the following: Good — and now that we have that out of the way, let's focus on other factors that are likely to be more important, including those mentioned by the letter writers. Population aging cannot be ignored, but it should not be at the top of the list of things to worry about in physician human resource planning at the aggregate level.
Frank T. Denton Department of Economics Amiram Gafni Department of Clinical Epidemiology and Biostatistics Byron G. Spencer Department of Economics McMaster University Hamilton, Ont.
References
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- 2.