BMI and cause‐specific hospital admissions and costs: The UK Biobank cohort study

Objective To estimate the effect of BMI on cause‐specific hospital admissions and costs in men and women is not well understood, and this study’s aim is to address this. Methods For 451,320 men and women aged 40 years or older recruited into the UK Biobank, followed up for 6 years on average, this study estimated annual rates and costs (at 2016 UK prices) of hospital admissions, overall and by diagnostic category (using International Classification of Diseases, Tenth Revision chapters), in relation to BMI. Results Among those who were never smokers, a 2‐kg/m2 higher BMI (above 20 kg/m2) was associated with a 6.2% (99% CI: 5.3% to 7.2%) higher admission rate and an 8.6% (99% CI: 7.3% to 10.0%) higher annual cost in men and with a 5.7% (99% CI: 4.9% to 6.6%) higher admission rate and an 8.4% (99% CI: 7.5% to 9.3%) higher annual cost in women. Higher BMI was associated with higher admission rates and costs for many types of health conditions, particularly for endocrine, skin, and musculoskeletal disorders in both men and women and for circulatory diseases in men. Conclusions BMI beyond healthy weight is strongly associated with higher annual rates of hospital admission and higher costs in both men and women across a wide range of health conditions.