Assessing existing technologies: the Manitoba study of common surgical procedures.

An overview of the Manitoba study of common surgical procedures is presented. The research is oriented toward describing and explaining the outcomes of nine relatively common procedures, using longitudinal data from the Manitoba Health Services Commission's population registry, medical claims, and physician claims. The research approach recognizes differences among surgical procedures, tailoring the analyses to specific characteristics of a given procedure. At the same time, this article describes the efforts made to achieve economies of scale in organizing the data base and writing the computer programs. The strategy used for assessing surgical risks and benefits is described at some length. Health services utilization before and after surgery is compared across small areas with widely differing surgical rates. Comparisons between surgical and other groups are suggested. The wealth of data permits a number of different types of studies. One study deals with patterns of surgical practice, types of operations performed, and risk characteristics of patients brought to surgery in areas with differing surgical rates. High-risk patients residing in high-rate areas are more likely to be operated upon than their counterparts in low-rate areas. A second study found that hysterectomy is apparently being used in situations where women have high rates of contact with the health care system before surgery; their rates of contact after surgery are almost as high. Ongoing activities in the research project are outlined.