Objectives This study investigated the impact of heat on the risk of hospital admission due to a range of health conditions in England. Design We used records of over 4 million hospital admissions in the summer months between 2008 and 2019, to construct daily time series of admissions in 32 837 census areas.
Coupled with high-resolution environmental data, we conducted a case time-series analysis using distributed-lag non-linear models to measure the lagged relationship between summertime temperature and risk of admission for a broad set of health conditions. We derived the relative risks of admission at the 99th compared with the 50th temperature percentile to understand the effect of extreme heat in each locality.
Setting The adult population of England (aged 18 years and older). Outcome measures Unplanned National Health Service (NHS) in-patient hospital admissions for cardiovascular, respiratory, genitourinary, metabolic and infectious diseases, along with their subcategories.
Results These conditions contributed more than 3.7 million admissions, of which over 1.5 million (42%) were for those aged 75 years and over.
BMJ Open published a clinical update in Research Highlights on 24 Jun 2026.
The item focuses on Extreme heat and cause-specific risk of hospital admission in the adult population in England: a case time series analysis.
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