School-age growth and development following infant feeding and/or water, sanitation, and hygiene interventions in rural Zimbabwe: long-term follow-up of a cluster-randomised trial

Abstract

Background: Few trials have explored long-term effects of interventions designed to reduce child stunting. We evaluated school-age outcomes in rural Zimbabwean children who received cluster-randomised water, sanitation and hygiene (WASH) and/or infant and young child feeding (IYCF) interventions from pregnancy up to 18 months of age.

Methods: The Sanitation Hygiene Infant Nutrition Efficacy (SHINE) trial enrolled pregnant women from two rural Zimbabwean districts (Chirumanzu and Shurugwi) between 2012 and 2015, and cluster-randomised them using a 2 × 2 factorial design to standard-of-care, WASH, IYCF, or combined WASH & IYCF, with a co-primary outcome of height-for-age Z-score and haemoglobin at 18 months (clinicaltrials.govNCT01824940). Children who were HIV-unexposed, age 7 years, and still living in Shurugwi district were eligible for this follow-up study (registered at PACTR 202201828512110) and measured between 1st April 2021 and 30th September 2022. The primary outcome at 7 years was cognitive function using the Kaufman Assessment Battery for Children (KABC-II). Secondary outcomes were executive function, literacy and numeracy, fine motor skills, socioemotional function, handgrip strength, broad jump distance, shuttle-run test distance, anthropometry, lean mass index, and skinfold thicknesses. Study nurses conducting assessments were blinded to intervention arm. Analysis followed a pre-registered statistical analysis plan. Intention-to-treat analyses using generalized estimating equations were used to assess the long-term effects of WASH and IYCF on each outcome, leveraging the factorial trial design. A pre-specified subgroup analysis by child sex was also performed.

Findings: Among 3989 HIV-negative women, 3676 children were assessed at age 18 months; of these, 1002 (510 female) were assessed at mean (SD) age 7.3 (0.2) years. There was no effect of IYCF or WASH on the KABC-II score or secondary cognitive outcomes, except a small improvement in socioemotional function in WASH arms (-0.98 points, 95% CI -1.73, -0.22, p = 0.01). Children in IYCF arms had higher handgrip strength (0.28 Kg, 95% CI 0.02, 0.53, p = 0.03); however, in the pre-specified subgroup analysis, improved handgrip strength was seen only in boys (0.53 Kg, 95% CI 0.19, 0.87 p = 0.002). There were no significant effects of either intervention on other outcomes.

Interpretation: Early-life IYCF and WASH led to few functional benefits by school-age. Interventions that are more comprehensive, delivered for longer, and include nurturing care should be considered to improve long-term cognitive and physical function.

Funding: Wellcome [220671/Z/20/Z, 108065/Z/15/Z]; NIH [R61HD103101]; Thrasher [15250]; and IMMANA [3.02].

Keywords: Child; Development; Nutrition; Stunting; WASH.

Fig. 1

Trial flow. SOC, Standard of care arm; IYCF, Infant and Young Child Feeding intervention arm; WASH, Water, sanitation and hygiene intervention arm; WASH + IYCF: combined arm.