Proportion of hospital readmissions deemed avoidable: a systematic review
- Carl van Walraven, MD MSc⇓,
- Carol Bennett, MSc,
- Alison Jennings, MA,
- Peter C. Austin, PhD,
- Alan J. Forster, MD MSc
- From the Faculty of Medicine (van Walraven, Forster), University of Ottawa, Ottawa, Ont.; the Ottawa Health Research Institute (van Walraven, Bennett, Jennings, Forster), Ottawa, Ont.; the Institute for Clinical Evaluative Sciences (van Walraven, Austin, Forster), Toronto, Ont.; and the Department of Health Management, Policy and Evaluation, and the Dalla Lana School of Public Health (Austin), University of Toronto, Toronto, Ont.
- Correspondence to:
Dr. Carl van Walraven, carlv{at}ohri.ca
Abstract
Background Readmissions to hospital are increasingly being used as an indicator of quality of care. However, this approach is valid only when we know what proportion of readmissions are avoidable. We conducted a systematic review of studies that measured the proportion of readmissions deemed avoidable. We examined how such readmissions were measured and estimated their prevalence.
Methods We searched the MEDLINE and EMBASE databases to identify all studies published from 1966 to July 2010 that reviewed hospital readmissions and that specified how many were classified as avoidable.
Results Our search strategy identified 34 studies. Three of the studies used combinations of administrative diagnostic codes to determine whether readmissions were avoidable. Criteria used in the remaining studies were subjective. Most of the studies were conducted at single teaching hospitals, did not consider information from the community or treating physicians, and used only one reviewer to decide whether readmissions were avoidable. The median proportion of readmissions deemed avoidable was 27.1% but varied from 5% to 79%. Three study-level factors (teaching status of hospital, whether all diagnoses or only some were considered, and length of follow-up) were significantly associated with the proportion of admissions deemed to be avoidable and explained some, but not all, of the heterogeneity between the studies.
Interpretation All but three of the studies used subjective criteria to determine whether readmissions were avoidable. Study methods had notable deficits and varied extensively, as did the proportion of readmissions deemed avoidable. The true proportion of hospital readmissions that are potentially avoidable remains unclear.
See related commentary by Goldfield at www.cmaj.ca/cgi/doi/10.1503/cmaj.110448
