Hajat S, Kovats RS, Lachowycz K. Heat-related and cold-related deaths in England and Wales: who is at risk

Public & Environmental Health Research Unit, London School of Hygiene & Tropical Medicine, London, UK.
Occupational and environmental medicine (Impact Factor: 3.27). 03/2007; 64(2):93-100. DOI: 10.1136/oem.2006.029017
Source: PubMed


Despite the high burden from exposure to both hot and cold weather each year in England and Wales, there has been relatively little investigation on who is most at risk, resulting in uncertainties in informing government interventions.
To determine the subgroups of the population that are most vulnerable to heat-related and cold-related mortality.
Ecological time-series study of daily mortality in all regions of England and Wales between 1993 and 2003, with postcode linkage of individual deaths to a UK database of all care and nursing homes, and 2001 UK census small-area indicators.
A risk of mortality was observed for both heat and cold exposure in all regions, with the strongest heat effects in London and strongest cold effects in the Eastern region. For all regions, a mean relative risk of 1.03 (95% confidence interval (CI) 1.02 to 1.03) was estimated per degree increase above the heat threshold, defined as the 95th centile of the temperature distribution in each region, and 1.06 (95% CI 1.05 to 1.06) per degree decrease below the cold threshold (set at the 5th centile). Elderly people, particularly those in nursing and care homes, were most vulnerable. The greatest risk of heat mortality was observed for respiratory and external causes, and in women, which remained after control for age. Vulnerability to either heat or cold was not modified by deprivation, except in rural populations where cold effects were slightly stronger in more deprived areas.
Interventions to reduce vulnerability to both hot and cold weather should target all elderly people. Specific interventions should also be developed for people in nursing and care homes as heat illness is easily preventable.

Download full-text


Available from: Sari Kovats
  • Source
    • "Additionally, this paper does not account for sociodemographic differences in population mortality. Studies in the US have identified sociodemographic groups as having differing relative vulnerabilities to high temperatures [55] [56], although this has been found not to be the case for the UK or Europe [6] [8] [56]. However, the higher underlying mortality rates for poorer social groups mean that they will also have higher absolute heat-related mortality burdens (for the same relative risk). "
    [Show abstract] [Hide abstract]
    ABSTRACT: With the predicted increase in heatwave frequency in the UK due to climate change, there has been an increasing research focus on mortality during hot weather. This paper examines the risk of mortality in London during hot weather by combining data on population age and distribution, Urban Heat Island (UHI), and dwelling propensity to overheat due to geometry and fabric characteristics derived using building physics in order to calculate the spatial variation in heat-related mortality risk across London. Spatial variation of heat-related mortality was found to reflect background mortality rates due to population age, while dwelling characteristics were found to cause a larger variation in temperature exposure (and therefore risk) than UHI. The highest levels of excess mortality were found in areas with larger elderly populations, towards the outskirts of the Greater London Authority (GLA).
    Full-text · Article · Sep 2015 · Urban Climate
    • "At the same time, identification of factors that modify the effects of extreme temperatures on mortality is also an issue of interest in the scientific community. A greater susceptibility has been reported for the elderly and female (Hajat et al. 2007; Analitis et al. 2008; Zhou et al. 2014; Zeng et al. 2014) and for those with lower socioeconomic status (Armstrong 2003; Hajat et al. 2007; Xu et al. 2013). Regarding the medical conditions and preexisting diseases that may confer susceptibility , results of previous studies from different regions are geographically heterogeneous (Schwartz 2005; Medina- Ramón et al. 2006; Madrigano et al. 2013; Zanobetti et al. 2013; Zhou et al. 2014). "
    [Show abstract] [Hide abstract]
    ABSTRACT: The short-term effects of ambient cold temperature on mortality have been well documented in the literature worldwide. However, less is known about which subpopulations are more vulnerable to death related to extreme cold. We aimed to examine the personal characteristics and underlying causes of death that modified the association between extreme cold and mortality in a case-only approach. Individual information of 197,680 deaths of natural causes, daily temperature, and air pollution concentrations in cool season (November-April) during 2002-2011 in Hong Kong were collected. Extreme cold was defined as those days with preceding week with a daily maximum temperature at or less than the 1st percentile of its distribution. Logistic regression models were used to estimate the effects of modification, further controlling for age, seasonal pattern, and air pollution. Sensitivity analyses were conducted by using the 5th percentile as cutoff point to define the extreme cold. Subjects with age of 85 and older were more vulnerable to extreme cold, with an odds ratio (OR) of 1.33 (95 % confidence interval (CI), 1.22-1.45). The greater risk of extreme cold-related mortality was observed for total cardiorespiratory diseases and several specific causes including hypertensive diseases, stroke, congestive heart failure, chronic obstructive pulmonary disease (COPD), and pneumonia. Hypertensive diseases exhibited the greatest vulnerability to extreme cold exposure, with an OR of 1.37 (95 % CI, 1.13-1.65). Sensitivity analyses showed the robustness of these effect modifications. This evidence on which subpopulations are vulnerable to the adverse effects of extreme cold is important to inform public health measures to minimize those effects.
    No preview · Article · Sep 2015 · International Journal of Biometeorology
  • Source
    • "In the UK, projections on the health impacts of climate change suggest a significant increase in temperature-related mortality in the absence of adaptive management (Hajat et al. 2014). While there is clear epidemiological evidence that elderly and very young people are particularly vulnerable to adverse effects of extreme temperatures (Worfolk 2000, Schwartz 2005, Hajat et al. 2007, O'Neill et al. 2009, Schifano et al. 2013), less attention is given to social, environmental, and technical risk dimensions that mediate heat wave vulnerability. There is evidence of the impact of disaster risk knowledge on the vulnerability of individuals to extreme heat (Abrahamson et al. 2009, Wolf et al. 2010), but less attention has been paid to the role of disaster risk knowledge in shaping organizational responses to heat wave risk. "

    Preview · Article · May 2015
Show more