Epidemiology of infectious disease–related death after release from prison, Washington state, United States, and Queensland, Australia: A cohort study

Objectives. People in prison may be at high risk for infectious diseases and have an elevated risk of death immediately after release compared with later; their risk of death is elevated for at least a decade after release. We compared rates, characteristics, and prison-related risk factors for infectious disease–related mortality among people released from prisons in Queensland, Australia, and Washington State, United States, regions with analogous available data. Methods. We analyzed data from retrospective cohort studies of people released from prison in Queensland (1997–2007, n=37,180) and Washington State (1999–2009, n=76,208) and linked identifiers from each cohort to its respective national death index. We estimated infectious disease–related mortality rates (deaths per person-years in community) and examined associations using Cox proportional hazard models. Results. The most frequent infectious disease–related underlying cause of death after release from prison was pneumonia (43%, 23/54 deaths) in the Australian cohort and viral hepatitis (40%, 69/171 deaths) in the U.S. cohort. The infectious disease–related mortality rate was significantly higher in the U.S. cohort than in the Australian cohort (51.2 vs. 26.5 deaths per 100,000 person-years; incidence rate ratio = 1.93, 95% confidence interval 1.42, 2.62). In both cohorts, increasing age was strongly associated with mortality from infectious diseases. Conclusion. Differences in the epidemiology of infectious disease–related mortality among people released from prison may reflect differences in patterns of community health service delivery in each region. These findings highlight the importance of preventing and treating hepatitis C and other infectious diseases during the transition from prison to the community.