FACTORS CONTRIBUTING TO PRACTICE VARIATION IN POSTSTROKE REHABILITATION

Objective. To analyze geographic variability in the utilization and co st of post-stroke medical care using multiple linear regression. Data Sources/Study Setting. A 20 percent random sample of Medicare benefici aries with an admission to an acute care hospital for stroke during th e first six months of 1991, supplemented by data from their Medicare c laims and beneficiary records, the Medicare Cost Reports for hospitals and nursing homes, and the Area Resource File. Study Design. Weighted least squares regression is used to analyze variations in poststroke practice patterns across 151 MSAs (Metropolitan Statistical Areas). Av erage post-stroke costs, utilization rates, and facility lengths of st ay are regressed on patient and market characteristics. Data Collectio n/Extraction Methods. For a six-month post-stroke interval, beneficiar y-level post-stroke costs and service utilization are averaged by MSA. Variables describing market conditions are then added to these MSA-le vel records. Principal Findings. Patient variables rarely explain more than a third of practice variation, and often they explain substantia lly less than that. Market variables (with some exception) tend to be relatively less important. Finally, one-half to two-thirds of the prac tice variation across MSAs is unexplained by the patient and market fa ctors measured in our data Conclusions. A substantial portion of inter -MSA variability in utilization and intensity of post-stroke rehabilit ation services cannot be explained by differences in patient character istics. Given the large practice differences observed across MSAs, it seems unlikely that unmeasured patient differences can account for muc h more of the practice differences.