Are 30-Day Hospital Readmissions Really a Good Measure of Quality?

A new analysis suggests that the 30-day hospital readmission indicator used by CMS to rate hospital quality and penalize acute care hospitals for excessive unplanned readmissions should be reconsidered as a measure of quality of care. Shorter intervals of 7 or fewer days are a more accurate measure of quality of hospital quality and care.

David L. Chin, PhD, of the Center for Healthcare Policy and Research at the University of California, Davis, and colleagues examined the 30-day risk of unplanned inpatient readmissions at the hospital level for Medicare patients ages 65 and older in California, Arizona, Florida, and New York for 3 conditions: acute myocardial infarction (AMI), pneumonia, and heart failure. The study, published in Health Affairs, found that hospital-level quality, assessed by calculating a measure known as the intracluster correlation coefficient (ICC), was highest on the first day after discharge and declined rapidly until it reached its lowest point after the seventh day postdischarge. The findings suggest that a 5- to 7-day “ascertainment interval” would better capture hospital-attributable readmissions, particularly when compared with 30-, 60-, or 90-day intervals, the authors said.

The ICC represents the proportion of risk explained by hospitals (between-hospital variation) compared with the total risk in the population (all variation) as an indicator of quality, because if readmissions are heavily influenced by hospital practices, between-hospital variation should be large compared with total variation, and the ICC should be relatively large. Conversely, if patient or household characteristics are dominant drivers of readmissions risk, then the ICC should be relatively small. The authors calculated the ICC across a range of postdischarge time intervals and conditions, while adjusting for the contribution of patient-level clinical risk factors. In this way, the study measures how hospital-level variation in readmission risk changes over time after discharge, independent of patient characteristics.

Current risk-standardized readmissions models used by CMS, which adjust only for patient age, sex, and clinical characteristics, are not adequate, the study authors say because their calculations suggest that most readmissions after the seventh day postdischarge were explained by community- and household-level factors beyond hospitals’ control. Thus, policy makers should consider taking a different direction with respect to the 30-day readmissions standard for hospitals.

While the 30-day all-cause, unplanned readmission rate has become widely used to measure a hospital’s performance in order to impose financial penalties on those facilities that have excess readmissions, there is little evidence that the 30-day rate reflects aspects of care that are under the hospital’s direct (or indirect) control, according to the authors.

“If the goal of current public policy is to encourage hospitals to assume responsibility for post-discharge adherence and primary care follow-up, then penalties assessed for readmissions within 30 days or longer periods might align appropriately,” they concluded. “However, if the goal is empowering patients and families to make healthcare choices informed by true differences in hospital performance, then a readmission interval of 7 days or fewer might be more accurate and equitable.”