Rousham 1994 (Cluster)

Methods	Cluster‐RCT Method to adjust for clustering: not adjusted Cluster unit: village Average cluster size: 114 ICCs: not reported Length of follow‐up: 18 months
Participants	All children living in endemic area Number analysed for primary outcome: 13 villages randomized containing 1402 children Age range: 2 to 6 years Inclusion criteria: children ages 2 to 6 years from 13 villages surrounding a mother and child health centre; subgroup living in 8 villages within waking distance of health centre analysed for additional outcomes Exclusion criteria: none stated
Interventions	Multiple doses vs placebo Mebendazole: 500 mg (Janssen) every 2 months; Placebo; Pyrantel pamoate and mebendazole: initial dose of 10 mg/kg pyrantel pamoate (Combantrin, Pfizer, UK) then mebendazole 500 mg bimonthly for 8 months (4 doses).
Outcomes	ANOVAs for change in z‐scores for z‐scores for height‐for‐age, weight‐for‐age, and weight‐for‐height (NCHS reference); Change in MUAC at 6, 12, and 18 months (no SD); Other outcomes measured but not reported: height; weight; stool examination for prevalence and intensity in subgroup (eggs/g: modified sedimentation technique); subgroup also analysed for intestinal permeability, albumin, alpha‐1‐antichymotrypsin, total protein every 2 months.
Notes	Location: Bangladesh Community category: 1 No adjustment made for cluster randomization Source of funding: the Overseas Development Administration and the University of Cambridge Maintenance Fund.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	The trial was described as randomized, no further details reported.
Allocation concealment (selection bias)	Unclear risk	No details reported.
Blinding (performance bias and detection bias) All outcomes	Low risk	Participants and field workers were blinded, unclear if assessment was blinded. "The treatment and placebo tablets were given in a double‐blind manner; neither the fieldworkers nor the parents were aware of the group to which they belonged".
Incomplete outcome data (attrition bias) All outcomes	Low risk	94% (1402/1476) of enrolled participants were evaluated. Inclusion of all randomized participants (number evaluable/number randomized): 94% (1402/1476).
Selective reporting (reporting bias)	Low risk	Not all pre‐specified outcomes reported.
Other bias	Low risk	Recruitment bias: unclear (not known if children shift clinics in the light of the intervention) Baseline imbalance: low (no differences apparent) Loss of clusters: low (none reported) Incorrect analysis: not adjusted (high risk) Comparability with RCTs randomizing individuals: unclear