Assessment tools: small area analysis.

Small area analysis, the examination of geographic variation in the medical care utilization of populations, provides a method for analyzing medical care resource use and can lead to improved medical care. Variations in rates of hospital admissions for most common causes of hospitalization are related to differences in the supply of medical care resources, such as hospital beds, and uncertainty in the outcomes of different diagnostic and therapeutic procedures. Introducing clinicians to practice variation can lead to process improvements. The article describes small area analysis and the limitations of this methodology.