Summary of findings for the main comparison. Any anthelmintic drug single dose compared to placebo for treating ascariasis.

Any anthelmintic drug single dose compared to placebo for treating ascariasis
Patient or population: children and adults Setting: school and community (United Republic of Tanzania, Haiti, Rwanda, Ethiopia, Guatemala, Republic de Cote d'Ivoire; 1983–2018) Intervention: any anthelmintic drug single dose Comparison: placebo
Outcomes	Anticipated absolute effects* (95% CI)		Relative effect (95% CI)	№ of participants (studies)	Certainty of the evidence (GRADE)	Comments
	Risk with placebo	Risk with any anthelmintic drug single dose
Parasitological cure assessed with: parasitological examination Follow‐up: range 14–60 days	16 per 100	93 per 100 (81 to 98)	RR 6.29 (3.91 to 10.12)	1578 (8 RCTs)	⊕⊕⊕⊝ Moderatea	Any anthelmintic as a single dose probably results in a large increase in parasitological cure compared to placebo.
Faecal egg count assessed with: ERR of epg (GM or AM) Follow‐up: range 14–60 days	The ERR of GM ranged from 96.1% to 100% in anthelmintic single‐dose group and from 11.7% to 33.9% in placebo group.		—	1020 (5 RCTs)	⊕⊕⊕⊕ High	Any anthelmintic as a single dose results in large reduction in faecal egg count compared to placebo.
Adverse events assessed with: report Follow‐up: range 14–60 days	The adverse events reported were few (headache, fever, myalgia, cough, epigastric pain, and diarrhoea) and similar among the groups.		—	744 (4 RCTs)	⊕⊕⊕⊝ Moderateb	Any anthelmintic as a single dose probably results in few adverse events compared to placebo.
*The risk in the intervention group (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). AM: arithmetic mean egg count; CI: confidence interval; epg: eggs per gram; ERR: egg reduction rate; GM: geometric mean egg count; RCT: randomized controlled trial; RR: risk ratio.
GRADE Working Group grades of evidence High certainty: we are very confident that the true effect lies close to that of the estimate of the effect. Moderate certainty: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low certainty: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect. Very low certainty: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect.

^aDowngraded one level: there was a high level of heterogeneity among trials not explained by subgroup analysis (I² = 86%).
 ^bDowngraded one level due to risk of performance bias.