Lai 1995

Methods	Quasi‐RCT Length of follow‐up: 2 years
Participants	All children living in endemic area Number analysed for primary outcome: 314 Mean age: 8 years Inclusion criteria: school children aged 8 who provided a stool sample Exclusion criteria: concurrent illness; anthelminth treatment in previous 3 months
Interventions	Multiple doses vs placebo Mebendazole plus pyrantel: 100 mg mebendazole and 200 mg pyrantel every 3 months for 2 years; Placebo: every 3 months for 2 years.
Outcomes	Measured: Hookworm, Trichuris, and Ascaris prevalence; Eggs/g faeces; Weight and height.
Notes	Location: Malaysia Community category: 1 No data used in meta‐analysis since SDs not provided Source of funding not reported.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Quasi‐randomized: block assignment design by school, then by sex, then by presence of worms as none, light, or moderate/heavy, and then by rank order of body weight in the group; used odd and even numbers; in urban area the odd numbered children were assigned to treatment; in the peri‐urban area the even numbered children were assigned to the treatment group.
Allocation concealment (selection bias)	Unclear risk	No details reported.
Blinding (performance bias and detection bias) All outcomes	High risk	Participants were blinded; trial staff not blinded to group assignment.
Incomplete outcome data (attrition bias) All outcomes	Low risk	89% (314/353) of randomized participants were evaluated. Inclusion of all randomized participants (number evaluable/number randomized): 89% (314/353).
Selective reporting (reporting bias)	Low risk	All stated outcomes reported.
Other bias	Low risk	No obvious other sources of bias.