Stephenson 1993.

Methods	Design: parallel group randomized trial Duration of study: September 1989 to July 1990 Follow‐up: 108 days
Participants	Country: Kenya Setting: school Number included in study: 328 Age: mean 10.5 years Sex: not reported Inclusion criteria: all available children in the lower grades (Standards I–V) in Mvindeni Primary School in Kwale District, Coast Province, Kenya Exclusion criteria: children with heavy hookworm egg counts (> 20,000 epg of faeces) at examination 1 or 2 Lost at follow‐up: 44 (13.4%) Number positive for A lumbricoides: 89 Number included in review: 89
Interventions	Treatment strategy: screening and treat all included participants Group 1: albendazole 200 mg 3 tablets (600 mg) single dose (n = 59) Group 2: placebo (n = 30)
Outcomes	Outcomes included:Ascaris prevalence pre‐ and post‐treatment, AM and GM epg Group 1 and 2 analysed together in review after the first round of treatment Outcomes not included in review: outcomes after the second round of treatment, anthropometric measures, anthelmintic efficacy for T trichiura and hookworm
Notes	Diagnostic technique: modified Kato‐Katz Funding support: supported in part by Thrasher Research Fund and SmithKline Beecham, Ltd.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "At exam 1, children were allocated at random within sex by descending hookworm egg count to placebo one dose or two dose groups."
Allocation concealment (selection bias)	Unclear risk	Details not reported.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Identical placebo.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "examinations were carried out with the same team of workers and were done in a blind fashion."
Incomplete outcome data (attrition bias) All outcomes	Low risk	44 (13.4%) participants lost at follow‐up and not included in analysis.
Selective reporting (reporting bias)	High risk	Adverse events not reported.
Other bias	Unclear risk	Quote: "Supported in part by Thrasher Research Fund and SmithKline Beecham, Ltd."