Review Article: Vulnerability to Heat-related Mortality: A Systematic Review, Meta-analysis, and Meta-regression Analysis.
BACKGROUND
Addressing vulnerability to heat-related mortality is a necessary step in the development of policies dictated by heat action plans. We aimed to provide a systematic assessment of the epidemiologic evidence regarding vulnerability to heat-related mortality.


METHODS
Studies assessing the association between high ambient temperature or heat waves and mortality among different subgroups and published between January 1980 and August 2014 were selected. Estimates of association for all the included subgroups were extracted. We assessed the presence of heterogeneous effects between subgroups conducting Cochran Q tests. We conducted random effect meta-analyses of ratios of relative risks (RRR) for high ambient temperature studies. We performed random effects meta-regression analyses to investigate factors associated with the magnitude of the RRR.


RESULTS
Sixty-one studies were included. Using the Cochran Q test, we consistently found evidence of vulnerability for the elderly ages >85 years. We found a pooled RRR of 0.99 (95% confidence interval [CI] = 0.97, 1.01) for male sex, 1.02 (95% CI = 1.01, 1.03) for age >65 years, 1.04 (95% CI = 1.02, 1.07) for ages >75 years, 1.03 (95% CI = 1.01, 1.05) for low individual socioeconomic status (SES), and 1.01 (95% CI = 0.99, 1.02) for low ecologic SES.


CONCLUSIONS
We found strongest evidence of heat-related vulnerability for the elderly ages >65 and >75 years and low SES groups (at the individual level). Studies are needed to clarify if other subgroups (e.g., children, people living alone) are also vulnerable to heat to inform public health programs.
From the aUniversité de Montréal, Département de Santé Environnementale et Santé au Travail, Montréal, QC, Canada; bEcole des Hautes Etudes en Santé Publique (EHESP) School of Public Health, Rennes, Sorbonne-Paris Cité, France; cINSERM U1085 (IRSET), Rennes, France; dDepartment of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, QC, Canada; and eInstitut National de Santé Publique du Québec, Montréal, QC, Canada.
Tarik
T
Benmarhnia
Séverine
S
Deguen
Jay S
JS
Kaufman
Audrey
A
Smargiassi
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000389:Air Conditioning / Q000706:statistics & numerical data; D004198:Disease Susceptibility; D005260:Female; D006358:Hot Temperature; D006801:Humans; D008297:Male; D017533:Marital Status / Q000706:statistics & numerical data; D009026:Mortality; D011634:Public Health; D012044:Regression Analysis; D012307:Risk Factors; D012737:Sex Factors; D012923:Social Class