Changes in preventable hospitalization patterns among the adults: a small area analysis of US states.

The study examines the variation and changes in preventable hospitalization (PH) rates across small areas over 1995-2005 in 5 US states for adults (aged 18-64 years). Using hospital discharge data from the Agency for Healthcare Research and Quality and contextual data from Health Resources and Services Administration, the study examines the role of managed care, primary care physician supply, and sociodemographic factors on adult PH rates. A stronger influence of minority and uninsured status, weaker contributions of managed care enrollment in the commercial as well as in the Medicaid markets, and weaker contributions of primary care density may have caused slower than expected reduction in adult PH rates.