County, not hospital itself, may influence readmission rates

Medicare might achieve better results by rewarding community-based strategies to reduce 30-day readmissions for heart failure, MI and pneumonia rather than penalize hospitals that don’t meet performance metrics. According to one study, much of the variation in rates boiled down to the county in which a hospital was located.

Medicare’s readmission reduction initiative withholds up to 3 percent of reimbursement to hospitals with lower-than-expected 30-day readmission rates for the three conditions, based on a risk-adjusted formula used by the Centers for Medicare & Medicaid Services (CMS). The penalty is designed to improve quality of care and save on costs. Jeph Herrin, PhD, of the Health Research & Educational Trust in Chicago, and colleagues speculated community factors that aren’t included in the risk adjustment might affect readmission rates as well.

They linked readmissions data from CMS Hospital Compare with hospital and county data, allowing county to serve as a proxy for community. Their final sample included 4,073 hospitals in 2,254 counties in the U.S. They calculated that 58 percent of the national variation in pooled readmission rates was at the county level.

“Expressed differently, the results suggest that individual hospital performance accounts for only 42 percent of the variation in pooled readmission rates across the United States,” they wrote.

Across counties, county characteristics explained 47.5 percent of the variation in rates. Measures of access to care such as the supply of general practitioners and specialists and the ratio of general practitioners to specialists were most strongly associated with readmissions. The number and quality of nursing homes also appeared to have an impact. Hospital factors such as teaching or safety-net status or bed size had only a modest effect on variance.

“That the majority of the unexplained variation in hospital readmission rates can be attributed to counties rather than hospitals suggests that narrowly targeting hospitals with reimbursement adjustments and other incentives can lead at best to marginal improvements in readmission rates; more effective policies might be directed at the wider system of care, including primary care and nursing home quality,” they suggested.

The study was published in the February issue of Health Services Research.