Ontario hospitals--mergers, shorter stays and readmissions.

OBJECTIVES This article examines the association between readmissions of pneumonia and acute myocardial infarction (AMI) patients to Ontario hospitals in 1998/99, and reductions in length of stay and recent hospital administrative mergers. DATA SOURCE The data are from the 1998/99 Discharge Abstract Database, maintained by the Canadian Institute for Health Information. ANALYTICAL TECHNIQUES Cross-tabulations were used to assess unadjusted associations between hospital and patient characteristics and readmission risk. Hierarchical nonlinear models were used to calculate odds of readmission, adjusting for hospital and patient characteristics. MAIN RESULTS Hospital characteristics that may indicate restructuring--a decrease in mean length of stay or a recent administrative merger--were not associated with readmission of pneumonia or AMI patients within 30 days of discharge. Patients with two or more related hospital admissions in the previous year were at increased risk of readmission.