Steele 1988a.

Study characteristics
Methods	This study was carried out in a primary care setting, and it was open. Intention‐to‐treat analysis was not carried out. This study was conducted in the UK and Germany.
Participants	207 participants were recruited: 18 dropped out. Inclusion criteria of the trial Adults and children Ordinary warts Warts on the hands or feet
Interventions	Weekly cotton wool bud cryotherapy versus SA/LA paint daily versus Both cryotherapy and SA/LA On alternate days, participants in all 3 treatment groups were instructed to soak their warts in warm water and abrade then with a pumice stone or emery board.
Outcomes	Outcomes of the trial Cure at 6 months
Notes	Multiple and mosaic plantar warts were excluded. Adverse effects were not assessed.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	This was randomly assigned using a random number tables. (page 256)
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 unlikely because of the application of the intervention. Quote (page 257): "Liquid nitrogen does not lend itself to a double blind trial."
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	This was unclear; no details were given.
Incomplete outcome data (attrition bias) All outcomes	Low risk	There were 13/129 withdrawals from the hand‐wart trial: 10/13 were irregular attendees; 2/13 withdrew because of pain; and 1/13 hospital were admissions, but it was not clear which groups the withdrawals were from. There were 5/78 withdrawals from the plantar‐wart trial: 4/5 were irregular attendees; 1/5 withdrew because of pain (groups not stated). (page 257)
Selective reporting (reporting bias)	Unclear risk	Adverse effects were not reported.