Sustained improvements in handwashing indicators more than 5 years after a cluster‐randomised, community‐based trial of handwashing promotion in Karachi, Pakistan

Abstract

To evaluate handwashing behaviour 5years after a handwashing intervention in Karachi, Pakistan. In 2003, we randomised neighbourhoods to control, handwashing promotion, or handwashing promotion and water treatment. Intervention households were given soap +/- water treatment product and weekly handwashing education for 9months. In 2009, we re-enrolled 461 households from the three study groups: control (160), handwashing (141), and handwashing+water treatment (160) and assessed hygiene-related outcomes, accounting for clustering. Intervention households were 3.4 times more likely than controls to have soap at their handwashing stations during the study visit [293/301 (97%) vs. 45/159 (28%), P<0.0001]. While nearly all households reported handwashing after toileting, intervention households more commonly reported handwashing before cooking [relative risk (RR) 1.2 (95% confidence interval (CI) 1.0-1.4)] and before meals [RR 1.7 (95% CI, 1.3-2.1)]. Control households cited a mean of 3.87 occasions for washing hands; handwashing households, 4.74 occasions; and handwashing+water treatment households, 4.78 occasions (P<0.0001). Households reported purchasing a mean of 0.65 (control), 0.91 (handwashing) and 1.1 (handwashing+water treatment) bars of soap/person/month (P<0.0001). Five years after receiving handwashing promotion, intervention households were more likely to have soap at the household handwashing station, know key times to wash hands and report purchasing more soap than controls, suggesting habituation of improved handwashing practices in this population. Intensive handwashing promotion may be an effective strategy for habituating hygiene behaviours and improving health.