Effect of a home-based health, nutrition, and responsive stimulation intervention and conditional cash transfers on child development and growth: a cluster-randomized controlled trial in Tanzania

Introduction Evidence on the effect of community health worker (CHW) interventions and conditional cash transfers (CCTs) on child growth and development in sub-Saharan Africa remains sparse. Methods We conducted a single-blind, cluster-randomized controlled trial of an integrated home-visiting health, nutrition, and responsive stimulation intervention alone and in combination with CCTs to promote antenatal and child clinic attendance from 2017 to 2019 in rural Morogoro region, Tanzania. Pregnant women and caregivers with a child <1□year of age were enrolled. Twelve villages were randomized to either a (i) CHW (n=200 participants), (ii) CHW+CCT (n=200), or (iii) control arm (n=193). An intention-to-treat analysis was conducted for the primary trial outcomes of child cognitive, language and motor development assessed with the Bayley Scales of Infant and Toddler Development and child length/height-for-age z-scores (HAZ) at 18-months of follow-up. Results The CHW and CHW+CCT interventions had beneficial effects on child cognitive development as compared to control (standardized mean difference (SMD): 0.15; 95% confidence interval (CI): 0.05, 0.24) and SMD: 0.18; 95% CI: 0.07, 0.28, respectively). The CHW+CCT intervention also had positive effects on language (SMD: 0.08; 95% CI: 0.01, 0.15) and motor development (SMD: 0.16; 95% CI: 0.03, 0.28). Both CHW and CHW+CCT interventions had no effect on HAZ in the primary analysis; however, there were statistically significant positive effects in multivariable analyses. The CHW+CCT group (mean difference: 3.0 visits; 95% CI: 2.1-4.0) and the CHW group (mean difference: 1.5 visits; 95% CI: 0.6-2.5) attended greater number of child health and growth monitoring clinic visits as compared to the control group. Conclusion Integrated CHW home-visiting interventions can improve child cognitive development and may have positive effects on linear growth. Combining CHWs with CCTs may provide additional benefits on clinic visit attendance and selected child development outcomes. Trial registration number ISRCTN10323949 Key Questions Box What is already known? Community health worker interventions that integrate health, nutrition and responsive stimulation components can improve child development but evidence from sub-Saharan Africa is limited. Conditional cash transfers can increase healthcare utilization but effects on child development and growth remain unclear. What are the new findings? An integrated home-visiting community health worker intervention benefited child cognitive development and may have improved child linear growth in rural Tanzania. Combining conditional cash transfers with the community health worker intervention increased child clinic visit attendance as intended and improved child cognitive, motor, and language development and may have improved child linear growth as compared to control. What do the new findings imply? Community health workers can improve child development and possibly child growth outcomes; however, additional research is needed to determine the intensity and frequency of visits to optimize impact as well as the direct and indirect mechanisms through which community health worker interventions work. Conditional cash transfers may provide additional benefits on clinic attendance and selected development domains as compared to community health workers alone; however, additional research is needed to directly compare integrated supply-side and demand-side strategies to promote child growth and development.