Mortality in a large community-based cohort of inner-city residents in Vancouver, Canada

Abstract

The Downtown Eastside is a robust and densely populated neighbourhood in Vancouver, Canada, that is characterized by low-income housing and drug use and a high prevalence of HIV infection. We evaluated mortality and excess mortality among the broader community of individuals living in this neighbourhood. The Community Health and Safety Evaluation is a community-based study of inner-city residents in the Downtown Eastside who were recruited in 2003 and 2004. Participants' data were linked with data in provincial virology and mortality databases retrospectively and prospectively for the period 1991-2009. Mortality and standardized mortality ratios (SMRs) were calculated for the period 2003-2009 to compare death rates in the study population with rates in the population of Vancouver. Among 2913 participants, 374 deaths occurred, for an all-cause mortality of 223 per 10 000 person-years (95% confidence interval [CI] 201-247 per 10 000 person-years). Compared with the population of Vancouver, significant excess mortality was observed in the study population (SMR 7.1, 95% CI 6.4-7.9). Excess mortality was higher among women (SMR 15.4, 95% CI 12.8-18.5) than among men (SMR 5.8, 95% CI 5.1-6.6). Although crude mortality increased with age, excess mortality was greatest among participants less than 35 years old (SMR 13.2, 95% CI 9.4-18.5) and those 35-39 years old (SMR 13.3, 95% CI 10.3-17.1). Excess risk was also elevated among participants with hepatitis C virus (HCV), HIV and HCV/HIV infection, with SMRs of 5.9 (95% CI 4.9-7.1), 19.2 (95% CI 12.8-28.9) and 23.0 (95% CI 19.3-27.4), respectively. Our study showed high mortality in this inner-city population, particularly when compared with the general population of Vancouver. Excess mortality was highest among women, younger participants and those infected with either HCV or HIV or both.