This is a prospective cohort study building upon the existing cohort study on the effectiveness of the Trekkers Family Enhancement Scheme. This study will sample 200 low-income parent-child pairs and follow them up for 24 months with yearly assessment on parental stress and child health using both subjective measures and objective physiological parameters. Additional data on parenting style, neighbourhood cohesion, child physical assault and neglect potential, parental mental health and HRQOL and family disharmony will also be collected at each assessment time point for testing mediating and moderating mechanisms between parental stress and child health. The baseline assessment will be carried out in 2016-17 with three repeated assessments after 6 months, 12 months, and 24 months.