Association between intensive handwashing promotion and child development in Karachi, Pakistan: a cluster randomized controlled trial.

Objective: To evaluate associations between handwashing promotion and child growth and development.

Design: Cluster randomized controlled trial.

Setting: Informal settlements in Karachi, Pakistan.

Participants: A total of 461 children who were enrolled in a trial of household-level handwashing promotion in 2003 and were younger than 8 years at reassessment in 2009.

Interventions: In 2003, neighborhoods were randomized to control (n = 9), handwashing promotion (n = 9), or handwashing promotion and drinking water treatment (n = 10); intervention households received free soap and weekly handwashing promotion for 9 months.

Main outcome measures: Anthropometrics and developmental quotients measured with the Battelle Developmental Inventory II at 5 to 7 years of age.

Results: Overall, 24.9% (95% CI, 20.0%-30.6%) and 22.1% (95% CI, 18.0%-26.8%) of children had z scores that were more than 2 SDs below the expected z scores for height and body mass index for age, respectively; anthropometrics did not differ significantly across study groups. Global developmental quotients averaged 104.4 (95% CI, 101.9-107.0) among intervention children and 98.3 (95% CI, 93.1-103.4) among control children (P = .04). Differences of similar magnitude were measured across adaptive, personal-social, communication, cognitive, and motor domains.

Conclusions: Although growth was similar across groups, children randomized to the handwashing promotion during their first 30 months of age attained global developmental quotients 0.4 SDs greater than those of control children at 5 to 7 years of age. These gains are comparable to those of at-risk children enrolled in publicly funded preschools in the United States and suggest that handwashing promotion could improve child well-being and societal productivity.

Trial registration: clinicaltrials.gov Identifier: NCT01538953.