Cost-benefit analysis of interventions to protect care home residents in England against heat risks.

We examine the cost-benefit of selected physical and behavioural interventions to reduce indoor temperatures and associated health risks in UK care homes during periods of hot weather typical of the projected future climate. Cases of heat-related mortality under selected temperature scenarios were modelled for three care home settings. Published temperature-mortality functions for care home residents of England and Wales were applied to life tables for care home populations. Building physics modelling was used to assess the effect of interventions on summer indoor temperatures and associated mortality risks. The monetised value of quality-adjusted life years gained was assessed in relation to the capital, energy and maintenance costs of each intervention over its lifespan under a range of assumptions. Sensitivity analyses were used to characterise model uncertainty. Under the assumption that those who die of heat have the life expectancy of an average care home resident, we found evidence for cost-effective interventions. The cost-effectiveness of interventions varied across care homes, depending on each building's specific characteristics. In a large, highly insulated care home with low thermal mass, increased thermal mass combined with window and door opening rules was the most cost-effective intervention; in a small care home with limited insulation and high thermal mass, active cooling in lounges using portable air-conditioners was most cost-effective; and in a medium sized care home with moderate insulation and thermal mass, shading combined with window and door opening rules was most cost-effective. Our results show that several interventions have the potential to be cost-effective in reducing heat-related risks to residents across a range of care home types. They also demonstrate that behavioural interventions, such as window and door opening, may be equally effective as physical interventions at reducing exposure to heat-related risks, provided they are fully adhered to.