How do perceived and objective measures of neighbourhood disadvantage vary over time? Results from a prospective-longitudinal study in the UK with implications for longitudinal research on neighbourhood effects on health

Theories of health outcomes often hypothesize that living in more socially and economically disadvantaged neighbourhoods will lead to worse health. Multiple measures of neighbourhood disadvantage are available to researchers, which may serve as better or worse proxies for each other across time. To inform longitudinal study design and interpretation we investigated how perceived and objective measures of neighbourhood disadvantage vary over time and the factors underlying this variation. Data were from 8,918 mothers with at least three time-points of neighbourhood data in the Avon Longitudinal Study of Parents and Children in the UK. We analyzed measures of objective (Indices of Multiple Deprivation) and perceived (neighbourhood quality, social cohesion, and stress) exposure to neighbourhood disadvantage at 10 time-points over 18 years. We used group-based trajectory modelling to determine the overlap in participants' trajectories on the different measures and evaluated the baseline factors associated with different perceived trajectories over time. There was evidence of heterogeneity in both perceived and objective measures of neighbourhood disadvantage over time (e.g., on the objective measure, 5% of participants moved to more deprived neighbourhoods, 11% moved to less deprived neighbourhoods, 20% consistently lived in deprived neighbourhoods, and 64% consistently lived in non-deprived neighbourhoods). Perceived social cohesion showed the weakest relationship with exposure to objective neighbourhood deprivation: most participants in each trajectory group of objective neighbourhood deprivation followed non-corresponding trajectories of perceived social cohesion (61-80%). Accounting for objective deprivation exposure, poorer socioeconomic and psychosocial indicators at baseline were associated with following more negative perceived neighbourhood trajectories (e.g., high neighbourhood stress) over time. Trajectories of perceived and objective measures of neighbourhood disadvantage varied over time, with the extent of variation depending on the time point of measurement and individual-level social factors. Researchers should be mindful of this variation when choosing and determining the timing of measures of neighbourhood disadvantage in longitudinal studies and when inferring effect mechanisms.