Mapping domains of early life determinants of future multimorbidity across three UK longitudinal cohort studies

Many studies use a reductionist approach to isolate the influence of one factor in childhood on multimorbidity rather than consider the combined effect of wider determinants. We explored how potential multiple early life determinants of multimorbidity can be characterised across three UK cohort studies. We used the National Child Development Study (NCDS), the 1970 British Cohort Study (BCS70), and the Aberdeen Children of the 1950s Study (ACONF) to identified early life variables that fit into 12 conceptualised domains of early life determinants of multimorbidity. Variables were assigned into 12 domains; principal component analysis reduced the dimensionality of the data and structured variables into subgroups. The data audit identified 7 domains in ACONF, 10 domains in NCDS and 12 domains in BCS70. Dominant components included maternal fertility histories within the prenatal, antenatal and birth domain, long-term illnesses within the child health domain, educational ability within the child education and health literacy domain, ethnicity within the demography domain, parental health behaviours within the transgenerational domain, housing within the socioeconomic domain and parental-child interactions within the parental-family domain. We demonstrated that if multiple large scale longitudinal studies are used, there is enough data available for researchers to consider conceptualising early life risk factors of multimorbidity across groups or domains. Such conceptualisation can help challenge the existing understanding of disease aetiology and develop new ideas for prevention of multimorbidity.