Residential greenness and wellbeing in the UK: a population-representative intersectional multilevel analysis

Residential greenness may support wellbeing, but evidence on whether these benefits differ across socially patterned populations remains limited. We examined associations between residential greenness and wellbeing across population strata defined by sex, ethnicity, and socioeconomic status (SES) based on data on urban residents from the UK Household Longitudinal Study, a population-representative and ethnically diverse sample from the UK (n = 26,322). Residential greenness was measured using neighbourhood Normalized Difference Vegetation Index (NDVI); wellbeing was operationalised as self-reported life satisfaction. We applied intersectional Multilevel Analysis of Individual Heterogeneity and Discriminatory Accuracy (MAIHDA), a multilevel approach that estimates associations across groups jointly defined by sex, ethnicity, and SES and assesses whether differences are additive or specific to particular combinations. The results showed that at the population level NDVI was positively associated with life satisfaction (with a 0.1-unit higher NDVI associated with a 0.054-point higher score on the seven-point life satisfaction scale). Associations ranged from 0.020 to 0.080 points higher life satisfaction per 0.1-unit higher NDVI. Positive associations were observed across all strata, although confidence intervals included the null for the high-SES White groups, which also had the smallest estimates. Between-stratum slope variation was fully accounted for by the additive contributions of sex, ethnicity, and SES, with the strongest evidence of effect modification observed for SES. Despite finding no residual departures from additivity, the stratum-specific estimates revealed a socially patterned profile structured primarily by SES, with high-SES White strata located at the lower end of the distribution and several lower-SES strata showing larger estimates. These findings suggest that population-average estimates can obscure socially patterned heterogeneity in greenness-wellbeing associations, even when that heterogeneity reflects additive social patterning rather than multiplicative intersectional effects. These results generally support an equity-oriented interpretation of urban greening and underscore the value of intersectional approaches in environmental health research.