Nokes 1992

Methods	RCT Length of follow‐up: 2.25 months (9 weeks)
Participants	Infected children identified by screening Number analysed for primary outcome: 103 Age range: 9 to 12 years Inclusion criteria: children from 3 schools in Mandeville; Trichuris egg counts > 1900, but low hookworm counts on 2 occasions before the trial separated by 3 months Exclusion criteria: twins; severe illness; physical handicaps; neurological disorders
Interventions	Single dose vs placebo Albendazole: 400 mg daily for 3 days (SmithKlineBeecham); Placebo: identical.
Outcomes	Cognitive tests: digit span forwards/backwards; arithmetic and coding from Wechsler Intelligence Scale for Children; fluency and listening comprehension from the Clinical Evaluation of Language functions; and matching familiar figures test. Not included in review: stool egg counts at baseline and 10 days (prevalence and arithmetic mean); height and weight (expressed as % NCHS standard) iron status; school attendance; IQ; socioeconomic status; educational opportunity measures at baseline. Outcomes not reported: nutritional outcomes at 9 weeks cited as too short a follow‐up period to demonstrate a change;school attendance only measured at baseline.
Notes	Location: Jamaica Community category: 1 There was an infected placebo group and an "uninfected control group" Source of funding not reported.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"Randomly assigned"; no further details reported.
Allocation concealment (selection bias)	Unclear risk	No details reported.
Blinding (performance bias and detection bias) All outcomes	Unclear risk	No details reported.
Incomplete outcome data (attrition bias) All outcomes	High risk	73% (103/140) of randomized participants were evaluated. Inclusion of all randomized participants (number evaluable/number randomized): 73% (103/140).
Selective reporting (reporting bias)	Unclear risk	Pyschometric tests reported; other outcomes such as nutrition not reported.
Other bias	Low risk	No obvious other source of bias.