Methods	RCT
Participants	100 women with CIN 1,2,3 Women with adequate colposcopy , no evidence of invasion, lesion no more than 5mm into canal
Interventions	Laser conisation Laser ablation
Outcomes	Duration of treatment Significant peri-operative bleeding Women’s subjective opinion of peri-operative pain (mild, moderate, severe) Secondary haemorrhage (seen in out-patients) Secondary haemorrhage (required admission) Adequate colposcopy Cervical stenosis Dysmennorrhoea Residual disease at 6, 12, 24 months
Notes	50 women randomised to laser conisation, 50 women randomised to laser ablation Haemostasis achieved by pressure with a cotton swab or Monsel solution Laser Excision 2mm margin to lesion and to a depth of 2-3mm Laser ablation to a depth of 10mm Intra-cervical 3% prilocaine with octapressin used pre-operatively
Risk of bias
Item	Authors’ judgement	Description
Adequate sequence generation?	Unclear	Not reported
Allocation concealment?	Yes	“Patients were randomised to treatment … by drawing sealed envelopes”
Blinding? All outcomes	Unclear	Not reported
Incomplete outcome data addressed? All outcomes	Yes	% of women analysed: 93/100 (93%) for residual disease By treatment arm Laser conisation: 45/50 (90%) Laser ablation: 48/50 (96%) All other outcomes analysed all 100 patients
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