Methods	RCT
Participants	200 women with CIN 1,2,3 Adequate colposcopy, no evidence of invasion
Interventions	Laser ablation Cryotherapy
Outcomes	Severe cramps Vasomotor symptoms Residual disease at 6 months.
Notes	100 women randomised to laser ablation, 100 randomised to cryotherapy Cryo coagulation (single freeze thaw technique) using a probe (18mm) with ice ball extending 5 mm beyond abnormal epithelium Laser ablation of all transformation zone No patient was lost to follow up
Risk of bias
Item	Authors’ judgement	Description
Adequate sequence generation?	Unclear	“The study was designed … in as objective a way as possible by alternating cases randomly insofar as possible on the bases of histologic grade and lesion size”. This study seems to deploy the method of minimisation and aims to minimise the imbalance between the number of patients in each treatment group over two important prognostic factors
Allocation concealment?	Unclear	Not reported
Blinding? All outcomes	Unclear	Not reported
Incomplete outcome data addressed? All outcomes	Yes	% of women analysed: 200/200 (100%)
Free of selective reporting?	Unclear	Insufficient information to permit judgement
Free of other bias?	Unclear	Insufficient information to assess whether an important risk of bias exists