Mass deworming to improve developmental health and wellbeing of children in low-income and middle-income countries: a systematic review and network meta-analysis

摘要

Background Soil-transmitted helminthiasis and schistosomiasis, considered among the neglected tropical diseases byudWHO, aff ect more than a third of the world’s population, with varying intensity of infection. We aimed to evaluate theudeff ects of mass deworming for soil-transmitted helminths (with or without deworming for schistosomiasis or cointerventions)udon growth, educational achievement, cognition, school attendance, quality of life, and adverse eff ectsudin children in endemic helminth areas.udMethods We searched 11 databases up to Jan 14, 2016, websites and trial registers, contacted authors, and reviewedudreference lists. We included studies published in any language of children aged 6 months to 16 years, with massuddeworming for soil-transmitted helminths or schistosomiasis (alone or in combination with other interventions) forud4 months or longer, that reported the primary outcomes of interest. We included randomised and quasi-randomisedudtrials, controlled before–after studies, interrupted time series, and quasi-experimental studies. We screened inudduplicate, then extracted data and appraised risk of bias in duplicate with a pre-tested form. We conducted randomeffudects meta-analysis and Bayesian network meta-analysis.udFindings We included 52 studies of duration 5 years or less with 1 108 541 children, and four long-term studiesud8–10 years after mass deworming programmes with more than 160 000 children. Overall risk of bias was moderate.udMass deworming for soil-transmitted helminths compared with controls led to little to no improvement in weight overuda period of about 12 months (0·99 kg, 95% credible interval [CrI] −0·09 to 0·28; moderate certainty evidence) or heightud(0·07 cm, 95% CrI −0·10 to 0·24; moderate certainty evidence), little to no diff erence in proportion stunted (eight fewerudper 1000 children, 95% CrI −48 to 32; high certainty evidence), cognition measured by short-term attention (−0·23 pointsudon a 100 point scale, 95% CI −0·56 to 0·14; high certainty evidence), school attendance (1% higher, 95% CI −1 to 3;udhigh certainty evidence), or mortality (one fewer per 1000 children, 95% CI −3 to 1; high certainty evidence). We foundudno data on quality of life and little evidence of adverse eff ects. Mass deworming for schistosomiasis might slightlyudincrease weight (0·41 kg, 95% CrI −0·20 to 0·91) and has little to no eff ect on height (low certainty evidence) andudcognition (moderate certainty evidence). Our analyses do not suggest indirect benefi ts for untreated children fromudbeing exposed to treated children in the community. We are uncertain about eff ects on long-term economic productivityud(hours worked), cognition, literacy, and school enrolment owing to very low certainty evidence. Results were consistentudacross sensitivity and subgroup analyses by age, worm prevalence, baseline nutritional status, infection status, impactudon worms, infection intensity, types of worms (ascaris, hookworm, or trichuris), risk of bias, cluster versus individualudtrials, compliance, and attrition.udInterpretation Mass deworming for soil-transmitted helminths with or without deworming for schistosomiasis hadudlittle eff ect. For schistosomiasis, mass deworming might be eff ective for weight but is probably ineff ective for height,udcognition, and attendance. Future research should assess which subset of children do benefi t from mass deworming,udif any, using individual participant data meta-analysis.