Body-mass-index-related disease burden in northwest UK—Global Burden of Disease methods in a subnational cross-sectional study: opportunities and challenges

Abstract

BackgroundThe UK Public Health White Paper (2010) acknowledges the widening disparities in health between the rich and poor. Public Health England authorises local authorities to deliver initiatives to improve population health. Such plans require evidence-based information using a validated, uniformly applicable tool. The aim of this study was to assess the feasibility of applying Global Burden of Disease (GBD) methods in Cheshire and Merseyside to (1) describe socioeconomic differences in years of life lost and years lived with disability from elevated body-mass index (BMI), and (2) assess the impact on inequalities of population shifts in BMI distribution. MethodsThe GBD risk assessment methodology was used, drawing on post-coded sources to link exposure and health outcomes to deprivation. Data on BMI by age and sex were obtained from local surveys. The index of multiple deprivation (IMD) was used to assess social deprivation. Health outcomes, including sequelae, were obtained from hospital episode statistics, national mortality data, and the cancer registry. FindingsIn a population of around 2 million, 40 000 cases of BMI-related disease and 8000 premature deaths occurred annually, with around 29 000 disability-adjusted life-years (DALYs) per 100 000 people (52% in males). The annual rate of DALYs in the most deprived quintile of the IMD was almost twice that in the least deprived. A shift downwards of 2 units in the BMI distribution led to an annual reduction of 7000 DALYs in the most deprived population, compared with 3500 DALYs in the least deprived. InterpretationAlthough subnational application of the GBD methodology was feasible in principle, significant limitations included poor-quality/incomplete BMI and morbidity data. Modelling may improve these, but could be constrained by the requirement for area-based linkage. The methodology can be applied to other geographical-based strata, including administrative units, urban/rural, etc, and can help define locally relevant policy to change risks across these strata. Local capacity building in applying the methodology and interpretation for policy will be required. FundingNational Health Services (Primary Care Trusts of Cheshire and Merseyside).