Unnatural death: a major but largely preventable cause-of-death among homeless people?

Background: We aimed to assess the contribution of specific causes-of-death to excess mortality of homeless persons and to identify differences in cause-specific mortality rates after vs. before implementing social policy measures.

Methods: We conducted a register based 10-year follow-up study of homeless adults in Rotterdam and calculated the proportion of deaths by cause-of-death in this cohort in the period 2001-2010. We estimated cause-specific mortality among the homeless compared to the general population with Standardized Mortality Ratios. We calculated Hazard Ratios adjusted for age and sex to compare mortality rates by cause-of-death among the homeless in the period after (2006-2010) vs. before (2001-2005) implementing social policy measures.

Results: Our cohort consisted of 2130 homeless persons with a mean age of 40, 3 years. Unnatural death, cardiovascular disease and cancer were the main causes of death. Compared to the general population of Rotterdam, the homeless had an excess risk of death for all causes. The largest mortality differences with Rotterdam citizens were observed for unnatural death (SMR 14.8, CI 11.5-18.7), infectious diseases (SMR 10.0, CI 5.2-17.5) and psychiatric disorders (SMR 7.7, CI 4.0-13.5). Mortality due to intentional injuries (suicide and homicide) differed significantly between the two study periods (HR 0.45, CI 0.20-0.97).

Conclusions: Reducing unnatural death should be a target in social policies aimed at improving the health of the homeless. We generated the hypothesis that social policies aimed at housing, work and improved contact with health care could be accompanied by less suicides and homicides within this vulnerable group.