de Haen 2006.

Study characteristics
Methods	The study was carried out in a primary care setting (in the participants' homes). This study was blinded. Intention‐to‐treat analysis was carried out. This study was conducted in Netherlands.
Participants	103 participants were recruited: 11 dropped out. Inclusion criteria of the trial Children Ordinary or refractory warts not specified Warts at any site
Interventions	Duct tape Placebo All participants (both groups) were asked to soak and rub the wart with a pumice stone once a week. Treatment continued for up to 6 weeks.
Outcomes	Outcomes of the trial Cure at 6 weeks
Notes	‐
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote (page 1122): "Randomization was performed in blocks of 10 stratified in 2 groups (single or multiple warts)." No further information was given on the method of randomisation. Comment: This was probably done.
Allocation concealment (selection bias)	Low risk	Quote (page 1122): A "central randomisation office that assigned the intervention and kept the randomisation key" was used in the study. Comment: This was adequate.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Participants and personnel were blinded. Quote (page 1122): "Patients were blinded to the hypothesis of the study." "Because it is unknown how duct tape achieves its possible effect, it was impossible to fabricate a placebo copy. Therefore, participants were not informed about the specific treatment investigated in this study." "To blind the assessor a second researcher who was not involved in the follow‐up measurements, applied the first treatment."
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote (page 1122): "One researcher performed the outcome measurements at school." This researcher was blind to the intervention.
Incomplete outcome data (attrition bias) All outcomes	Low risk	From 103 randomised participants, 11 children discontinued treatment: 8 in the duct tape group and 3 in the placebo group. Reasons were given; 3 in the treatment group stopped because of adverse effects. Comment: Table 3 on page 1124 of the study report reports adverse effects for only 47 out of 51 randomised to duct tape because of "missing values". All 52 participants in the placebo group were accounted for. This was not thought to introduce significant bias into the study.
Selective reporting (reporting bias)	Low risk	All prespecified outcomes were reported.