Research Activities April 2013, No. 392
Factors identified that influence preventable hospitalization rates in small areas over time
Patient Safety and Quality
Two new papers by AHRQ researcher, Jayasree Basu, Ph.D., and colleagues used small area analysis to explore how the rate of preventable hospitalizations over time (1995–2005) in adults is affected by the extent of managed care, primary care physician supply, and patient sociodemographic factors. A lower rate of preventable hospitalizations, also known as ambulatory care-sensitive condition admissions, is considered an accepted indicator of access to quality primary care. Both studies used AHRQ’s Health Care Utilization Project (HCUP)–State Inpatient Databases for 1995 and 2005, and analysis of small areas known as primary care service areas (PCSAs). They are briefly summarized here.
Basu, J. (2012, August). "Preventable hospitalizations and Medicare Managed Care: A small area analysis." American Journal of Managed Care 18(8), pp. 3280-3290.
In this study, Dr. Basu developed an area-level estimate of preventable hospitalization rates and examined how these rates varied with percentage of elderly (ages 65 and above) managed care patients in PCSAs of Arizona, Massachusetts, and New York in 1995 and 2005. The unadjusted statistics showed that the proportion of elderly hospitalized beneficiaries enrolled in Medicare managed care plans increased from a mean of 2 percent in 1995 to 11 percent in 2005, while preventable hospitalization rates for elderly residents fell from a mean of 190.68 per 1,000 discharges in 1995 to 175.65 per 1,000 discharges in 2005 in these three States.
The multivariate regression analysis revealed that, although the proportion of enrollment under Medicare managed care was inversely related to preventable hospitalization rates in 1995, this negative relationship became substantially weaker (smaller in absolute value and not statistically significant) by 2005. According to the author, the results could be explained by the growth of private fee-for-service types of managed care plans and the resultant decline in emphasis on care coordination relative to health maintenance organization plans.
Basu, J., Thumula, V., and Mobley, L.R. (2012, July-September). "Changes in preventable hospitalization patterns among adults. A small area analysis of U.S. States." Journal of Ambulatory Care Management 35(3), pp.3280-3290.
Dr. Basu and colleagues conducted a similar analysis for nonelderly adults aged 18–64 years using all-payer data from AHRQ’s HCUP–State Inpatient Databases for 1995 and 2005 for five States (Arizona, California, Massachusetts, New Jersey, and New York).
They found that factors leading to higher preventable hospitalization rates (being uninsured, being enrolled in Medicaid fee-for-service, belonging to a minority subgroup, being in the 45–64 year age group) exerted a stronger impact on preventable hospitalization trends for adults than those associated with declines in these hospitalizations (primary care physician density, private or Medicaid managed care). The authors concluded that 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 preventable hospitalization rates in nonelderly adults.