Shifts in mortality during a hot weather event in Vancouver, British Columbia: rapid assessment with case-only analysis.

Abstract

We assessed shifts in patterns of mortality during a hot weather event in greater Vancouver, British Columbia. We used a case-only analysis to compare characteristics of individuals who died during the hottest week of 2009 with those who died (1) during earlier summer weeks in 2009 and (2) during the same calendar weeks in the summers of 2001 through 2008. Compared with the 8 previous weeks of 2009, odds of mortality during the summer's hottest week were highest in the 65 to 74 years age category, compared with the 85 years and older category (odds ratio [OR] = 1.47; 95% confidence interval [CI] = 1.06, 2.03). The number of deaths at home increased over deaths in hospitals or institutions (OR = 1.43; 95% CI = 1.10, 1.86). Densely populated administrative health areas were more affected. A shift toward deaths at home suggests that in-home-based protective measures should be part of planning for hot weather events in greater Vancouver. Targeting should be considered for those aged 65 to 74 years. The case-only approach is quick and easy to apply and can provide useful information about localized, time-limited events.