Childhood socioeconomic circumstances and adult multimorbidity: A Systematic review and metaanalysis

Abstract Background Childhood socioeconomic disadvantage (SED) is a public health concern in Europe, where >20% of children face poverty/social exclusion. It is a foundational health determinant prioritised through initiatives eg. European Child Guarantee. Multimorbidity (MM),co-occurrence of ≥ 2 chronic conditions,is also rising, especially among disadvantaged groups. Yet long-term impact of early-life SED on adult MM remains underexplored. Methods We conducted PROSPERO-registered systematic review (CRD42024588657) searching four databases for observational studies quantifying associations between childhood SED and adult MM. Random-effects metaanalyses were performed where feasible; heterogeneity was assessed with I². Where metaanalysis was infeasible, effect direction synthesis was used. Risk of bias (RoB) was assessed via ROBINS-E; certainty graded using GRADE. Results From 5,617 records, 10 studies met inclusion criteria. Most were cross-sectional and used self-reported outcomes. Exposures included perceived childhood economic adversity(n = 6), parental education(n = 4), parental occupation(n = 1), and composite measures(n = 3). Findings were mixed. Several studies reported harmful associations, but directions and magnitudes varied. Metaanalysis of perceived adversity showed no clear association (OR 1.03; 95% CI: 0.84-1.27; I²=94.4%). Pooled ORs for father's and mother's education were 0.95 (95% CI: 0.66-1.37; I²=66.8%) and 1.07 (95% CI: 0.70-1.61; I²=36.9%), respectively. RII estimates ranged from 0.46-2.06, with inconsistent patterns across exposures/settings. All studies were high/very high RoB; evidence certainty was very low. Conclusions Evidence linking childhood SED to adult MM is inconclusive and heterogeneous. Studies suggest potential harmful associations but very low certainty and methodological limitations preclude firm conclusions. Reducing childhood poverty remains a public health priority, but further high-quality research is needed to clarify long-term impacts on MM. Key messages • Despite limited evidence childhood socioeconomic disadvantage appears to be consistently linked to higher adult multimorbidity, with strongest associations for parental education and occupation. • To inform action on child poverty and chronic disease, including in the European union, causal research is needed on how early-life policies can reduce long-term multimorbidity and health inequality.