Small area analysis: descriptive epidemiology in health services research

Small area analysis is descriptive epidemiology applied to health care events. Several methodological issues complicate such studies. Nevertheless, it is possible to derive several conclusions about the determinants of regional variation in medical care use from the small area analysis literature. Most of these conclusions are specific to the procedures, times, and places studied. Changes in technology, economic incentives, and epidemiological factors may invalidate study findings. Nevertheless, small area analysis studies are useful management tools if performed periodically rather than as one-time events. Small area analysis can contribute to our understanding and control of costs, quality, and the accessibility of care, and thus have relevance for both management and policy.