Out of various quality measures, pressure ulcer prevalence in particular predicts whether a nursing home will readmit residents to the hospital, according to newly published findings in HSR: Health Services Research.

Investigators analyzed 4,000 hospitals’ publicly reported readmission rates associated with pneumonia, myocardial infarction and heart failure between 2007 and 2010. By linking this data to information at the county level, from sources such as Nursing Home Compare and the U.S. Census, the researchers determined how much impact community factors had on readmissions.

Contrary to some previous research, the investigators found that the quality of nursing homes could affect hospital readmission rates in a given county.

Skilled nursing facilities with a high percentage of high-risk, long-stay residents with pressure sores were more likely to readmit people to the hospital, the researchers found. The percentage of long-stay residents with an increased need for help also correlated with a facility’s readmission rate, they determined.

The percentage of residents with a urinary tract infection, the rate of nursing home vaccinations and the number of restrained residents were not found to be significant in predicting readmissions.

In general, nearly 60% of the variation in hospitals’ readmission rates can be explained by factors at the county level that are largely outside the hospitals’ control, the researchers found. In addition to nursing home quality, the availability of general practitioners had a strong effect on readmissions. Demographic factors also came into play. Higher readmissions figures are linked to counties with a significant proportion of unmarried people and lower educational attainment.

Because hospitals have such limited control over these factors, penalizing acute care providers is not likely to improve readmissions rates, the study authors concluded. Better policies might address “the wider system of care, including primary care and nursing home quality,” they wrote.

Skilled nursing facilities’ payments will be affected by their hospital readmission rates starting in 2018, under a law passed last week.