title: Impacts of cold weather on all-cause and cause-specific mortality in Texas, 1990-2011.
abstract: Cold weather was estimated to account for more than half of weather-related deaths in the U.S. during 2006-2010. Studies have shown that cold-related excessive mortality is especially relevant with decreasing latitude or in regions with mild winter. However, only limited studies have been conducted in the southern U.S. The purpose of our study is to examine impacts of cold weather on mortality in 12 major Texas Metropolitan Areas (MSAs) for the 22-year period, 1990-2011. Our study used a two-stage approach to examine the cold-mortality association. We first applied distributed lag non-linear models (DLNM) to 12 major MSAs to estimate cold effects for each area. A random effects meta-analysis was then used to estimate pooled effects. Age-stratified and cause-specific mortalities were modeled separately for each MSA. Most of the MSAs were associated with an increased risk in mortality ranging from 0.1% to 5.0% with a 1 °C decrease in temperature below the cold thresholds. Higher increased mortality risks were generally observed in MSAs with higher average daily mean temperatures and lower latitudes. Pooled effect estimate was 1.58% (95% Confidence Interval (CI) [0.81, 2.37]) increase in all-cause mortality risk with a 1 °C decrease in temperature. Cold wave effects in Texas were also examined, and several MSAs along the Texas Gulf Coast showed statistically significant cold wave-mortality associations. Effects of cold on all-cause mortality were highest among people over 75 years old (1.86%, 95% CI [1.09, 2.63]). Pooled estimates for cause-specific mortality were strongest in myocardial infarction (4.30%, 95% CI [1.18, 7.51]), followed by respiratory diseases (3.17%, 95% CI [0.26, 6.17]) and ischemic heart diseases (2.54%, 95% CI [1.08, 4.02]). In conclusion, cold weather generally increases mortality risk significantly in Texas, and the cold effects vary with MSAs, age groups, and cause-specific deaths.
authors.affiliation: Department of Epidemiology, Human Genetics and Environmental Sciences, The University of Texas Health Science Center at Houston (UTHealth) School of Public Health, Houston, TX, USA.
authors.forename: Tsun-Hsuan
authors.initials: TH
authors.lastname: Chen
authors.affiliation: Department of Biostatistics, The University of Texas Health Science Center at Houston (UTHealth) School of Public Health, Houston, TX, USA.
authors.forename: Xiao
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Epidemiology, Human Genetics and Environmental Sciences, The University of Texas Health Science Center at Houston (UTHealth) School of Public Health, Houston, TX, USA.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Department of Epidemiology, Human Genetics and Environmental Sciences, The University of Texas Health Science Center at Houston (UTHealth) School of Public Health, Houston, TX, USA; Southwest Center for Occupational and Environmental Health, The University of Texas Health Science Center at Houston (UTHealth) School of Public Health, Houston, TX, USA. Electronic address: kai.zhang@uth.tmc.edu.
authors.forename: Kai
authors.initials: K
authors.lastname: Zhang
mesh_terms: D002423:Cause of Death / Q000639:trends; D003080:Cold Temperature; D005260:Female; D006358:Hot Temperature; D006801:Humans; D008297:Male; D008875:Middle Aged; D009026:Mortality / Q000639:trends*; D009203:Myocardial Infarction; D017711:Nonlinear Dynamics; D012120:Respiration Disorders; D012306:Risk; D012621:Seasons; D013696:Temperature; D013781:Texas / Q000453:epidemiology; D014887:Weather
keywords: Cold weather; Heart disease; Mortality; Spatial heterogeneity; Temperature