Ambient Temperature and Cardiorespiratory Morbidity: A Systematic Review and Meta-analysis

• Published in: Epidemiology (Cambridge, Mass.) Mass.), 2012-07, Vol.23 (4), p.594-606
• Main Authors: Turner, Lyle R, Barnett, Adrian G, Connell, Des, Tong, Shilu
• Format: Article
• Language: English
• Subjects: Bayes Theorem; Biological and medical sciences; Cardiovascular Diseases - etiology; Epidemiology; General aspects; Hot Temperature - adverse effects; Humans; Medical sciences; Miscellaneous; Public health. Hygiene; Public health. Hygiene-occupational medicine; Respiratory Tract Diseases - etiology
• ISSN: 1044-3983; 1531-5487
• DOI: 10.1097/EDE.0b013e3182572795

BACKGROUND:The effect of extreme temperature has become an increasing public health concern. Evaluating the impact of ambient temperature on morbidity has received less attention than its impact on mortality. METHODS:We performed a systematic literature review and extracted quantitative estimates of the effects of hot temperatures on cardiorespiratory morbidity. There were too few studies on effects of cold temperatures to warrant a summary. Pooled estimates of effects of heat were calculated using a Bayesian hierarchical approach that allowed multiple results to be included from the same study, particularly results at different latitudes and with varying lagged effects. RESULTS:Twenty-one studies were included in the final meta-analysis. The pooled results suggest an increase of 3.2% (95% posterior interval = −3.2% to 10.1%) in respiratory morbidity with 1°C increase on hot days. No apparent association was observed for cardiovascular morbidity (−0.5% [−3.0% to 2.1%]). The length of lags had inconsistent effects on the risk of respiratory and cardiovascular morbidity, whereas latitude had little effect on either. CONCLUSIONS:The effects of temperature on cardiorespiratory morbidity seemed to be smaller and more variable than previous findings related to mortality.