Trends in length of stay and rates of readmission in Massachusetts: implications for monitoring quality of care.

In this study, we examined lengths of stay and readmission rates for all Medicare patients discharged from Massachusetts acute care hospitals from October 1982 through September 1986. Using multivariate time series models, we controlled for case mix and assessed trends over time and the impact of prospective payment on lengths of stay and rates of readmission within 7, 14, and 30 days of discharge. We examined patterns for patients overall and for those admitted initially with one of several specific medical conditions or for a surgical procedure. Over the four years, lengths of stay decreased by 25% overall and by 12% to 38% for the individual conditions studied (all p less than .05). A small part of this decrease was associated with prospective payment. Overall readmission rates within 7 and 14 days increased by approximately 10% (p less than .05), although the increase was not statistically associated with prospective payment. Readmission rates for individual medical and surgical conditions were not significantly changed. Further study should assess whether the change in overall rates reflects lower quality care.