Hospital readmissions--are they predictable and avoidable?

In the context of limited resources in the healthcare system, factors that can be used as indicators for the effective use of diagnostic and therapeutic management of patients are of interest. The rate of hospital readmission (RA) is a potentially important parameter of quality in hospital care. In the present preliminary study, our aim was to measure the rate of readmissions, and to qualify the readmissions as avoidable or not. PRINCIPLES/METHODS: We performed this pilot study at the Department of Internal Medicine (DIM) of the Kantonsspital Winterthur (KSW). Between March 1st. and May 31st 1998 all patients admitted to our hospital were included in the study. Each patient was followed up for a period of 90 days after discharge. RA was classified as planned, unplanned, avoidable or unavoidable. Only the first RA of a patient was investigated. RAs were divided into those occurring within 30 and those occurring within 90 days of discharge.

884 index admissions (IA) were recorded. 83 patients (9.4%) died and 28 (3.2%) were referred to another clinic in the KSW. These 111 patients were excluded from the analysis. 773 (87.4%) patients were discharged from the DIM and are taken as 100% for the sake of calculation of the rates of RA. 95 (12.3%) RAs occurred within 30 days, 68 (8.8%, 95%-CI 6.8-10.8) of these being RAs related to the IA. 27 (3.5%) had no relation to the IA. 36 (4.7%) of these 68 RAs were planned and 32 (4.1%) were unplanned. Three unplanned RAs (0.4%) were considered to have been avoidable. When the observation period was extended to 90 days, 151 (19.5%) RAs occurred. 100 (12.9%) of the RAs were related to the IA. Of these 100 RAs 46 (5.9%) were planned and 54 (7.0%) were unplanned. Of these 54 RAs 10 (1.3%) were considered to have been avoidable. The highest rate of RAs occurred within the first 10 days of discharge, followed by a substantial decrease in RAs over the next 20 days and a constant low rate over the next 60 days. Unplanned RAs occurred in 59.3% within the first 30 days. Patients admitted on a Friday had the longest length of stay (LOS) in hospital and those admitted on a Sunday, the shortest.

The present pilot study indicates that RA should be monitored regularly. Most RAs occurred within 30 days of discharge. Extension of the observation period to 90 days did not change the overall conclusions.