Banihashemi 2008.

Study characteristics
Methods	This study was carried out in a secondary care setting. This study was blinded. Intention‐to‐treat analysis was not carried out. This study was conducted in Singapore.
Participants	60 participants were recruited: 7 dropped out. The average age of the participant was 15.6 years in the intervention group and 16.4 years in the control group. Inclusion criteria of the trial Adults or children not specified Ordinary warts Warts on the hands only
Interventions	Cryotherapy (cryotherapy was done with a cotton swab dipped into liquid nitrogen and then applied on the warts for 10 to 20 seconds every week) 80% phenol was applied on the dry lesions with a cotton swab every week.
Outcomes	Outcomes of the trial Cure at 6 weeks
Notes	‐
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote (page 1035): "Patients were randomly divided into two groups." Comment: The method used was simple randomisation according to the method of Lachin 1981 (additional information came from the trial investigator).
Allocation concealment (selection bias)	Unclear risk	The allocation concealment was unclear; no information was given.
Blinding of participants and personnel (performance bias) All outcomes	High risk	The trial investigators said: "Patients and the first dermatologist who treated them were alert about the medication." Comment: This was not blinded.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Outcome assessors were blinded to the treatment (additional information came from the trial investigator).
Incomplete outcome data (attrition bias) All outcomes	High risk	7 cases in the phenol group were not followed up. Quote (page 1036): "Four did not complete the follow‐up period and three could not tolerate burning sensation." Comment: Uneven distribution across the groups was likely to introduce bias.
Selective reporting (reporting bias)	Low risk	All prespecified outcomes were reported.