Factors associated with unplanned hospital readmission among patients 65 years of age and older in a Medicare managed care plan

PURPOSE: Unplanned hospital readmission within 30 days of discharge is cons idered a "sentinel event" for poor quality. Patients at high risk for this adverse event could be targeted for interventions designed to reduce their risk of readmission. The purpose of this study was to identify patient char acteristics and risk factors at discharge associated with unplanned readmis sion within 30 days of hospital discharge. SUBJECTS AND METHODS: We performed a matched case-control study among patie nts in a Medicare managed care plan who had been admitted to an academic ho spital. The cases were patients aged 65 years or older who were urgently or emergently readmitted to the hospital within 30 days of discharge. One con trol patient who was not readmitted within 30 days was matched to each case by principal diagnosis. The medical records of the first admission of the cases and the admission of the controls underwent review (blinded to case-c ontrol status) to determine the patient's baseline demographic characterist ics, comorbid conditions, previous health care utilization, and functional status. The records were also reviewed to assess risk factors on discharge, including clinical instability, inability to ambulate and feed, mental sta tus changes, number of discharge medications, and discharge disposition. RESULTS: Five factors were independently associated (P <0.05) with unplanne d readmission within 30 days. These included four baseline patient characte ristics: age 80 years or older [odds ratio = 1.8; 95% confidence interval ( CI), 1.02-3.2], previous admission within 30 days (odds ratio = 2.3; 95% CI , 1.2-4.6), five or more medical comorbidities (odds ratio = 2.6; 95% CI, 1 .5-4.7), and history of depression (odds ratio = 3.2; 95% CI, 1.4-7.9); and one discharge factor: lack of documented patient or family education (odds ratio = 2.3; 95% CI, 1.2-4.5). CONCLUSIONS: If validated, these factors may identify patients at high risk of readmission. They suggest that interventions, such as improved discharg e education programs, may reduce unplanned readmission. (C) 1999 by Excerpt a Medica, Inc.