Title: The impact of home energy efficiency interventions and winter fuel payments on winter- and cold-related mortality and morbidity in England: evaluation of a natural experiment
Funder: Department of Health (England)

Abstract: It has been long recognized that the UK has a large and unacceptable burden of excess winter mortality and morbidity (generally upward of 25000 excess winter deaths each year) which is greater than that of many comparable northern European countries with colder climates. Although part of the winter excess is attributable to influenza and other seasonal infections time-series studies suggest the major part of the seasonal burden is related to exposure to cold.[12] Theoretical considerations and some direct evidence from the UK New Zealand and elsewhere suggest that housing may play an important role in determining that vulnerability[34] though it is also recognized that exposures to cold through outdoor excursions may also be important. There has therefore been much interest in and debate about the contribution that interventions on housing quality may have on winter- and cold-related mortality and morbidity especially in the context of rapidly worsening UK figures on fuel poverty (caused mainly by recent upward global trends in energy prices) and recent severe winters.Over the next few decades there will be major investments in the housing sector driven in large measure by (i) policies aimed at reducing household energy use and greenhouse gas (GHG) emissions to meet legally-binding obligations of the Climate Change Act (2008) and (ii) considerations of health in particular the assumed benefits of improved insulation and energy efficiency for winter- and cold-related deaths and illness. However these investments may be very costly and they have the potential for adverse as well as positive effects on health[5] if energy efficiency is in part achieved through reduced ventilation.The Department of Energy and Climate Change (DECC) have been interested in the modelling the effects of home energy efficiency interventions on health in part because health impacts are a potentially important element in guiding policy decisions. In synthesizing evidence for such a model a number of crucial evidence gaps became apparent. Among the most important is the lack of direct evidence on cold-related mortality and harder health outcomes such as hospital admission. Much of the scientific literature on home energy efficiency and health is dominated by small-scale short-term assessments often inadequately controlled and using self-reported measures as key outcomes. No study published to date has been able to make a direct assessment of the impact of home energy efficiency on mortality and only to very limited to degree (mainly focused on specific patient groups) has any study examined emergency hospital admissions. This is mainly because of the extremely large sample sizes needed to test such impacts (remembering that cold-related deaths and hospital admissions are only a small part of all deaths and admissions – and identifiable only through statistical comparisons) such that randomized controlled trials with mortality as the outcome are effectively precluded.This is a major gap in knowledge not only because of its central relevance to policies aimed at tackling excess winter mortality/morbidity in the UK but also because the crucial place such evidence has for the major choices needed in housing policies in general given the context of the large investment needed for climate change mitigation strategies. Moreover we cannot assess the full economic and NHS benefits of such investments because of reliance on old and untested assumptions.However because of several unique data sources in the UK it is now possible to attempt an evaluation of mortality and hospital admission impacts through natural experiment. Key is the emerging availability of nationwide data on housing energy efficiency interventions compiled into a national database by the Energy Savings Trust (EST). This database is the Homes Energy Efficiency Database (HEED) which was established to ‘help monitor and target carbon reduction and fuel poverty work’. HEED tracks house-by-house the sustainable energy characteristics of the UKs housing stock using data gathered from a wide range of sources including energy suppliers government grant managing agents local authorities home energy checks as well as EST programmes (examples include EEC/CERT fuel poverty programmes Low Carbon Buildings Programme CIGA Corgi). HEED includes data on insulation measures heating systems appliances and micro-generation installations along with property survey information. It now covers approximately 50% of the UKs homes (over 13 million homes) with property- and date-specific details of such energy efficiency interventions over the last decade or so. By linking nationwide to postcoded mortality and hospital admission statistics this data base for the first time makes it possible to address the evidence gap on the relationship between home energy efficiency and cold mortality/morbidity through direct measurement in a well-powered empirical study. We believe evidence will be invaluable in providing important new empirical evidence that has bearing on a wide range of policy areas including health protection housing policies and NHS demands and costs; and it will provide evidence on the potential for housing investment/improvement to reduce health inequalities.[6] It has the potential to be a key element in decisions on major areas of policy formulation over coming years. It will be a unique study with an important contribution to the world scientific and policy literature.[1] Wilkinson P et al. Vulnerability to winter mortality in elderly people in Britain. BMJ 2004; 329(7467):647[2] Hajat S et al. Heat-related and cold-related deaths in England and Wales: who is at risk?OEM. 2007 Feb;64(2):93-100[3] Wilkinson P. Social and environmental determinants of excess winter death in England 1986-1996. York: JRF; 2001[4] Jackson G et al. Reduced acute hospitalisation with the healthy housing programme. JECH. 2011 Jul;65(7):588-93[5] Wilkinson P et al. Impact on public health of strategies to reduce greenhouse gas emissions: household energy. Lancet 2009 Dec 5; 374(9705):1917-29[6] Howden-Chapman P. Housing and inequalities in health. JECH 2002;56:645-646


Research activity codes: 3.2 INTERVENTIONS TO ALTER PHYSICAL AND BIOLOGICAL ENVIRONMENTAL RISKS
Health categories: GENERIC HEALTH RELEVANCE