Berth‐Jones 1992a.

Study characteristics
Methods	This study was carried out in a secondary care setting, and it was open. Intention‐to‐treat analysis was not carried out. This study was conducted in the UK.
Participants	400 participants were recruited: 77 dropped out. Inclusion criteria of the trial Adults and children Mixed types of warts Warts on the hands or feet
Interventions	3‐weekly cryotherapy No cryotherapy 3‐weekly cryotherapy was applied with a cotton wool bud + SA/LA versus no cryotherapy.
Outcomes	Outcomes of the trial Cure at 3 months
Notes	Cure rates were expressed as percentages only.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	It was stated that the trial was randomised, but no details were given.
Allocation concealment (selection bias)	Unclear risk	This was unclear; no details were given.
Blinding of participants and personnel (performance bias) All outcomes	High risk	This was inadequate; there was no blinding.
Blinding of outcome assessment (detection bias) All outcomes	High risk	This was inadequate; there was no blinding.
Incomplete outcome data (attrition bias) All outcomes	High risk	77 randomised participants were lost to follow up at 3 months with no reasons given, although they were balanced demographically and across the treatment groups.
Selective reporting (reporting bias)	Low risk	The only outcome, 'cure rate', was reported.