Quantifying and visualising heterogeneity in cumulative adverse childhood experiences scores

IMPORTANCEAdverse childhood experience (ACE) scores mask substantial heterogeneity within the 2-, 3-, and [≥]4-ACE exposure categories. The magnitude of this heterogeneity has not been sufficiently quantified. OBJECTIVETo quantify and visualise the heterogeneity of ACE scores. DESIGNCross-sectional analysis of the 2023 National Survey of Childrens Health, an address-based, nationally representative survey. SETTINGUS households. PARTICIPANTSA national sample of 385,000 addresses was drawn. Between 23 June 2023 and 19 January 2024, caregivers of children aged 0-17 years completed screening and topical questionnaires; 55,162 of 70,187 eligible households completed the topical questionnaire. EXPOSURESLifetime exposure to 10 ACEs, assessed via caregiver report: economic hardship; parental divorce/separation; household mental illness; household substance use; parental incarceration; domestic violence; racial discrimination; neighbourhood violence; health- or disability-based discrimination; and parental death. MAIN OUTCOMES AND MEASURESHeterogeneity of ACE co-occurrence within the 2-, 3-, and [≥]4-ACE exposure categories, quantified using combinatorial coverage (CC; proportion of possible co-occurrence patterns observed) and visualised with an UpSet plot of item combinations with unweighted n [≥] 30. RESULTSAnalyses used complete ACE data (N = 51,468; 93.3% of the total sample); co-occurrence analyses were restricted to children with [≥]2 ACEs (n = 7,897). Across the 2-, 3-, and [≥]4-ACE categories, 582 of 1,013 possible combinations were observed: all 45/45 patterns for 2 ACEs (CC2 = 1.00), 110/120 for 3 ACEs (CC3 = 0.917) and 427/848 for [≥]4 ACEs (CC[≥]4 = 0.504). Of the 582 distinct combinations, 50 met the display threshold, accounting for 5,204 (66%) of the 7,897 children with [≥]2 ACEs: 23, 15 and 12 for 2, 3 and [≥]4 ACEs, respectively. Certain ACEs recurred disproportionately among these intersections: parental divorce/separation appeared in 34 of 50 patterns, household substance use in 23 and household mental illness in 20. CONCLUSIONS AND RELEVANCEIn this nationally representative sample of US children, ACE scores masked substantial heterogeneity in exposure patterns within the 2-, 3-, and [≥]4-ACE categories. Simple heterogeneity diagnostics, such as combinatorial coverage and UpSet plots, can make this heterogeneity explicit and may prompt pattern-specific analyses of outcomes. Key PointsO_ST_ABSQuestionC_ST_ABSHow heterogeneous are cumulative adverse childhood experience (ACE) scores, and how can this heterogeneity be quantified and visualised? FindingsIn a nationally representative cross-sectional survey of 51,468 US children, 582 of 1,013 theoretically possible ACE combinations among those with [≥]2 ACEs were observed: all 45/45 patterns for 2 ACEs, 110/120 for 3 ACEs and 427/848 for [≥]4 ACEs. When visualised with an UpSet plot, some individual ACEs recurred disproportionately among the 50 most common co-occurrence patterns, which together accounted for 5,204 (66%) of the 7,897 children with [≥]2 ACEs. MeaningACE scores mask substantial heterogeneity within the 2-, 3- and [≥]4-ACE exposure categories, risking misleading inferences about which children are at highest risk; this heterogeneity can be made explicit using a simple metric and visualisation technique.