The association between temperature variability and mortality: an international collaborative study

Introduction: The evidence is limited for the impacts of temperature variability (TV) within or between days on mortality. In this study, we applied a novel method to calculate TV, and investigated the TV-mortality associations using a large multi-country data set. Methods: We collected daily time series data of temperature and mortality from 372 locations in 12 countries/regions with a wide range of climates (Australia, Brazil, Canada, China, Japan, Moldova, South Korea, Spain, Taiwan, Thailand, UK, and USA). We developed a novel method to calculate TV using the standard deviation of current day’s and preceding days’ minimum and maximum temperatures. Two-stage analyses were used to assess the relation between TV and mortality. Firstly, a Poisson regression model allowing over-dispersion was used to estimate the community-specific TV-mortality relation, after controlling for a long-term trend, seasonality, day of the week, and main effects of daily mean temperature up to 21 days. In the second stage, a me...