Abstract
Moving to a new house is common in childhood, particularly in New Zealand (NZ) where residential mobility rates are among the highest in the world. However, evidence regarding the prevalence of residential mobility and the implications of moving during early childhood is limited and little is known for NZ children specifically. This thesis addressed research questions about the prevalence of residential mobility and associations with health and wellbeing outcomes among NZ children using data from the Integrated Data Infrastructure (IDI).
A systematic literature review and narrative synthesis (thematic analysis) of research on childhood outcomes associated with residential mobility was undertaken. To identify possible differential patterns among findings, five themes were identified: learning and academic achievement; internalising and externalising behaviours; health risk and problem behaviours; mental health, wellbeing, and relationships; and, physical health and access to services. Findings among studies on residential mobility in young children were mixed, although associations between residential mobility and adverse outcomes were mainly reported. A conceptual framework drawn from the literature review and synthesis and developmental and social capital theory was developed, illustrating the hypothesised links between residential mobility and health and wellbeing outcomes.
Next, three retrospective cohort studies were conducted using a population-based child cohort drawn from the IDI linked administrative dataset. The main cohort comprised more than 300,000 children born since 2004, who appeared in the Before School Check database, a multi-component health and development screen universally administered to four-year-old NZ children. This includes the Strengths and Difficulties Questionnaire, a measure of children’s socioemotional and behavioural wellbeing. In Study 1, regression analyses showed residential mobility was associated with increased socioemotional and behavioural difficulties at four years of age (adjusted β = 0.16). Importantly, this association was linear, with each additional move associated with an increase in socioemotional and behavioural difficulties. In Study 2, residential mobility at two years of age was associated with increased risks for adverse health outcomes, including all-cause hospitalisations (aRR = 1.09), between two and four years of age. Lastly, in Study 3, residential mobility at four years of age was associated with a greater likelihood of school interventions (aRR = 1.06), adverse health outcomes including all-cause hospitalisations (aRR = 1.05), and grommet/aspiration procedures (aRR = 1.11) at eight years of age, and incomplete immunisation status (aOR = 0.96) at five years of age. Analyses with only Māori children from the cohort revealed a similar pattern of findings, although with slightly lower effect size estimates.
Policy and practice implications of these findings are discussed in the context of health equity and housing stability, particularly for children from low-income households and those living in rental housing. Avenues for future research are suggested, emphasising longitudinal studies, residential mobility in the context of other housing characteristics, identifying groups of children for whom residential mobility is likely to have the most impact, and seeking greater understanding of children’s perspectives of residential mobility.
Overall, this thesis provides population-level evidence that residential mobility in early childhood is consistently associated with small adverse effects across a range of health and wellbeing outcomes among NZ children.