Hospital readmissions in a community-based sample of homeless adults: a matched-cohort study

Background — Hospital readmission rates are a widely used quality indicator that may be elevated in disadvantaged populations.

Objective — The objective of this study was to compare the hospital readmission rate among individuals experiencing homelessness with that of a low-income matched control group, and to identify risk factors associated with readmission within the group experiencing homelessness.

Design — We conducted a 1:1 matched cohort study comparing 30-day hospital readmission rates between homeless patients and low-income controls matched on age, sex and primary reason for admission. Multivariate analyses using generalized estimating equations were used to assess risk factors associated with 30-day readmission in the homeless cohort.

Participants — This study examined a cohort of 1,165 homeless adults recruited at homeless shelters and meal programs in Toronto, Ontario, between December 6, 2004, and December 20, 2005.

Main Measures — The primary outcome was the occurrence of an unplanned medical or surgical readmission within 30 days of discharge from hospital.

Key Results — Between December 6^th, 2004 and March 31^st, 2009, homeless participants (N= 203) had 478 hospitalizations and a 30-day readmission rate of 22.2%, compared to 300 hospitalizations and a readmission rate of 7.0% among matched controls (OR= 3.79, 95% CI 1.93-7.39). In the homeless cohort, having a primary care physician (OR=2.65, 95% CI 1.05-6.73) and leaving against medical advice (OR=1.96, 95% CI 0.99-3.86) were associated with an increased risk of 30-day readmission.

Conclusions — Homeless patients had nearly four times the odds of being readmitted within 30-days as compared to low-income controls matched on age, sex and primary reason for admission to hospital. Further research is needed to evaluate interventions to reduce readmissions among this patient population.