Cohort profile: Understanding the influence of early life environments and health and social service system contacts over time and across generations through the Western Australian Aboriginal Child Health Survey (WAACHS) Linked Data Study.

Purpose: Despite the volume of accumulating knowledge from prospective Aboriginal cohort studies, longitudinal data describing developmental trajectories in health and well-being is limited. The linkage of child and carer cohorts from a historical cross-sectional survey with longitudinal health-service and social-service administrative data has created a unique and powerful data resource that underpins the Western Australian Aboriginal Child Health Survey (WAACHS) linked data study. This study aims to provide evidence-based information to Aboriginal communities across Western Australia, governments and non-government agencies on the heterogeneous life trajectories of Aboriginal children and families.