A Cochrane review on the interventions for reducing adverse health effects of high temperature and heatwaves

Abstract

Background: Even in the field of climate change and environmental health there is a need to for robust, systematic and transparent methods of research synthesis to define policy and support decision makers. Environmental and research agencies have started to translate methods from evidence-based medicine into environmental health. In the field of exposure to heatwaves, public health interventions have been implemented in several countries with a poor or lacking evidence-base. This systematic review is focused on public health interventions aimed to reduce, in the short or in the long-term, the adverse effects of high temperatures and heatwaves. Methods: We searched Pubmed, Embase and other bibliographic databases to identify relevant studies (inception-July 2015) using a detailed search strategies. Inclusion criteria were: RCT and observational studies with a control group and quantitative effect measures. Two reviewers extracted data independently and assessed risk of bias using a modified version of the Cochrane risk of bias tool. Results: We identified 6323 records of which 8 studies met all inclusion criteria. Included studies had a very high risk of selection bias, contamination and heterogeneity in study design prohibited a meta-analysis. They showed weak evidence on effectiveness for educational and home interventions (2 RCT); limited evidence on cooling measures (2 cohort studies), and urban interventions (4 CBA). Conclusions: Evidence on the effectiveness of interventions in the field of heat prevention is limited and not conclusive due to the exposure characteristics and the risk of bias associated to nonrandomized studies. Despite the uptake of systematic methods is promising in the field of environmental health, the process for the synthesis of evidence needs improvements and discussion.