Sustainability of Benefits from Parenting Interventions Delivered Through Health Services: Follow-Up at Age 6 Years of a Cluster Randomized Trial

Abstract

Background: There is strong global demand for parenting interventions feasible and cost effective at scale. Effect sizes are usually lower at scale and there is little information on sustainability of gains following smaller initial impact. Methods: A cluster randomized trial of two parenting interventions was conducted through 20 health centres in Jamaica. The centres were randomly assigned to 4 groups, control (n=150 mother-child pairs), health centre intervention (n=146), home-visit intervention (n=50) or both (n=50) using a computer-generated randomization sequence. Interventions were implemented from age 3-18 months and each intervention benefited cognitive development at 18 months (effect size 0.34-0.38SD). Children were reassessed at 6 years (n=262, 66.2% of those enrolled) to determine any benefits to IQ, school readiness and behaviour, and parenting behaviour. Loss to follow-up was not significantly different by treatment. Inverse probability weighting and Lee bounds were used to adjust for loss to follow-up, and multilevel regression analyses conducted with random effects at the health centre level. Findings: There were no significant benefits to any child outcomes at age 6 years or to parenting behaviour. Lee bounds estimates confirmed that effects remained indistinguishable from zero and in no case were both bounds statistically different from zero. Interpretation: Lack of sustained benefits may be related to small initial effect size and low intensity of the intervention that ended very young at age 18 months. The sample was also less disadvantaged than in prior Jamaican studies. The findings have implications for intervention design, in particular, duration, intensity and targeting. Clinical Trial Number: The original trial is registered with the ISRCTN Register, identifier number ISRCTN43108304 Funding Statement: This project was funded by the Inter-American Development Bank. Declaration of Interests: Dr Lopez-Boo is employed by the Inter-American Development Bank; the other authors have no no competing interests to declare. Ethics Approval Statement: Ethical approval for the study was obtained from the University of the West Indies Ethics Committee.