Ambient temperature and risk of cardiovascular hospitalization: An updated systematic review and meta-analysis

Dung Phung; Phong K Thai; Yuming Guo; Lidia Morawska; Shannon Rutherford; Cordia Chu

doi:10.1016/j.scitotenv.2016.01.154

Ambient temperature and risk of cardiovascular hospitalization: An updated systematic review and meta-analysis

Sci Total Environ. 2016 Apr 15:550:1084-1102. doi: 10.1016/j.scitotenv.2016.01.154. Epub 2016 Feb 9.

Authors

Dung Phung¹, Phong K Thai², Yuming Guo³, Lidia Morawska⁴, Shannon Rutherford⁵, Cordia Chu⁵

Affiliations

¹ Centre for Environment and Population Health, Griffith University, Australia. Electronic address: d.phung@griffith.edu.au.
² International Laboratory for Air Quality & Health, Queensland University of Technology, Australia. Electronic address: phong.thai@qut.edu.au.
³ Division of Epidemiology and Biostatistics, School of Public Health, University of Queensland, Australia.
⁴ International Laboratory for Air Quality & Health, Queensland University of Technology, Australia.
⁵ Centre for Environment and Population Health, Griffith University, Australia.

PMID: 26871555
DOI: 10.1016/j.scitotenv.2016.01.154

Abstract

The association between temperatures and risk of cardiovascular mortality has been recognized but the association drawn from previous meta-analysis was weak due to the lack of sufficient studies. This paper presented a review with updated reports in the literature about the risk of cardiovascular hospitalization in relation to different temperature exposures and examined the dose-response relationship of temperature-cardiovascular hospitalization by change in units of temperature, latitudes, and lag days. The pooled effect sizes were calculated for cold, heat, heatwave, and diurnal variation using random-effects meta-analysis, and the dose-response relationship of temperature-cardiovascular admission was modelled using random-effect meta-regression. The Cochrane Q-test and index of heterogeneity (I(2)) were used to evaluate heterogeneity, and Egger's test was used to evaluate publication bias. Sixty-four studies were included in meta-analysis. The pooled results suggest that for a change in temperature condition, the risk of cardiovascular hospitalization increased 2.8% (RR, 1.028; 95% CI, 1.021-1.035) for cold exposure, 2.2% (RR, 1.022; 95% CI, 1.006-1.039) for heatwave exposure, and 0.7% (RR, 1.007; 95% CI, 1.002-1.012) for an increase in diurnal temperature. However no association was observed for heat exposure. The significant dose-response relationship of temperature - cardiovascular admission was found with cold exposure and diurnal temperature. Increase in one-day lag caused a marginal reduction in risk of cardiovascular hospitalizations for cold exposure and diurnal variation, and increase in latitude was associated with a decrease in risk of cardiovascular hospitalizations for diurnal temperature only. There is a significant short-term effect of cold exposure, heatwave and diurnal variation on cardiovascular hospitalizations. Further research is needed to understand the temperature-cardiovascular relationship for different climate areas.

Keywords: Cardiovascular admission; Cold exposure; Diurnal temperature; Heatwave; Temperature exposure.

Publication types

Meta-Analysis
Research Support, Non-U.S. Gov't
Review
Systematic Review

MeSH terms

Cardiovascular Diseases / epidemiology*
Environmental Exposure / statistics & numerical data*
Hospitalization / trends*
Temperature*