Full Length Article High temperature and risk of hospitalizations, and effect modifying potential of socio-economic conditions: A multi-province study in the tropical Mekong Delta Region Dung Phung a, ⁎, Yuming Guo b , Huong T.L. Nguyen c , Shannon Rutherford a , Scott Baum a , Cordia Chu a a Centre for Environment and Population Health, Griffith University, Australia b Division of Epidemiology and Biostatistics, School of Public Health, University of Queensland, Australia c Health Environment Management Agency, Ministry of Health, Viet Nam abstract article info Article history: Received 6 December 2015 Received in revised form 1 March 2016 Accepted 25 March 2016 Available online xxxx The Mekong Delta Region (MDR) in Vietnam is highly vulnerable to extreme weather related to climate change. However there have been hardly any studies on temperature-hospitalization relationships. The objectives of this study were to examine temperature-hospitalization relationship and to evaluate the effects of socio-economic factors on the risk of hospitalizations due to high temperature in the MDR. The Generalized Linear and Distributed Lag Models were used to examine hospitalizations for extreme temper- ature for each of the 13 provinces in the MDR. A random-effects meta-analysis was used to estimate the pooled risk for all causes, and for infectious, cardiovascular, and respiratory diseases sorted by sex and age groups. Random-effects meta-regression was used to evaluate the effect of socio-economic factors on the temperature- hospitalization association. For 1 °C increase in average temperature, the risk of hospital admissions increased by 1.3% (95% CI, 0.9–1.8) for all causes, 2.2% (95% CI, 1.4–3.1) for infectious diseases, and 1.1% (95% CI, 0.5–1.7) for respiratory diseases. However the result was inconsistent for cardiovascular diseases. Meta-regression showed population density, poverty rate, and illiteracy rate increased the risk of hospitalization due to high temperature, while higher household income, houses using safe water, and houses using hygienic toilets reduced this risk. In the MDR, high temperatures have a significant impact on hospitalizations for infectious and respiratory dis- eases. Our findings have important implications for better understanding the future impacts of climate change on residents of the MDR. Adaptation programs that consider the risk and protective factors should be developed to protect residents from extreme temperature conditions. © 2016 Elsevier Ltd. All rights reserved. Keywords: Temperature Hospitalisations Mekong Delta Vietnam Climate change 1. Introduction There is increasing scientific evidence that rising anthropogenic greenhouse gas emissions have led to global warming, which results in more frequent and intense extreme weather events such as high tem- peratures (IPCC, 2013; Mcmichael et al., 2006). In many location, a sig- nificant increase in the number of hospitalizations is associated with high temperatures (Faunt et al., 1995; Juopperi et al., 2002; Michelozzi et al., 2009), and previous studies have suggested that high tempera- tures are associated with elevated risks of both communicable (Phung et al., 2015e; Phung et al., 2015c; Phung et al., 2014) and non- communicable diseases (Ebi et al., 2004; Schwartz et al., 2004; Bayentin et al., 2010; Oshige et al., 2006; Turner et al., 2012a; Phung et al., 2015a). Nevertheless, the evidence for the effects of high temper- atures on hospital admissions is less conclusive, even though the effect on mortality has been reported worldwide (Huang et al., 2012; Yang et al., 2015; Guo et al., 2014; Gasparrini et al., 2015). For example, stud- ies have indicated that high temperatures are associated with elevated hospital admissions due to cardio-respiratory diseases in several US cit- ies (Konken et al., 2003; Lin et al., 2009; Shwartz et al., 2004). However, some European studies have found no significant effects of high temper- atures on admissions due to cardiovascular causes (Kovats et al., 2004; Linares and Diaz, 2008; Michelozzi et al., 2009), and the effects of tem- peratures on admissions vary inconsistently with sex and age (Phung et al., 2015a). Moreover, most previous studies have been conducted in developed countries that have a temperate climate. There is a lack of research on temperature-hospitalization relationships in developing countries with subtropical and tropical climates (Basu, 2009; Kovats et al., 2004; Michelozzi et al., 2009;Phung et al., 2015a). The Mekong Delta Region (MDR), a tropical region of 13 provinces in Vietnam, is considered one of the areas in South-East Asia most Environment International 92–93 (2016) 77–86 ⁎ Corresponding author at: Centre for Environment and Population Health, Nathan Campus, Griffith University, 179 Kessels Road, Nathan, Brisbane, Queensland 4111, Australia. E-mail address: d.phung@griffith.edu.au (D. Phung). http://dx.doi.org/10.1016/j.envint.2016.03.034 0160-4120/© 2016 Elsevier Ltd. All rights reserved. Contents lists available at ScienceDirect Environment International journal homepage: www.elsevier.com/locate/envint