Hall 2004.

Methods	Randomised controlled trial Trial duration: 7 years and 5 months, from February 1990 to July 1997 Trial location: 14 centres across the United Kingdom
Participants	Number of participants: 300 randomised (interferon‐149, control‐151) Inclusion criteria: Patients had histologically proven epithelial ovarian cancer that showed no evidence of disease progression after post‐operative chemotherapy. The percentage of participants with FIGO stage I, II, III and IV ovarian cancer in the interferon group was 7%, 22%, 63% and 15% while in the chemotherapy group was 8%, 13%, 64% and 15% respectively Exclusion criteria: not specified
Interventions	Intervention: Interferon‐alpha: INF‐α 2a (Roferon‐A, Roche) (4.5 mega‐units subcutaneously 3 days per week). Interferon was continued until disease progression or in response to toxicity or patient request Control: No maintenance treatment
Outcomes	Overall survival (OS) Progression free survival (PFS), definition was not given Toxicity/adverse event (flu‐like symptoms, fatigue, nausea/vomiting, neurological, dyspnoea, depression/anxiety, skin change/rash, alopecia, arthralgia/arthritis, insomnia, haematological, hepatic, injection site reaction, other, not stated)
Notes	Ethics approval: study was approved by the Local Research Ethics Commitee of each participating centre Informed consent: written informed consent was obtained from patients prior to randomisation Funding: not mentioned Correspondence with authors: g.hall@leeds.ac.uk on date on 3rd July 2012
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not described how randomisation was done
Allocation concealment (selection bias)	Unclear risk	Not mentioned
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not described if participants were blinded to the treatment assigned. Control group did not receive any treatment
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not described if outcome assessors were blinded to treatment assignment but inlikely to have any effect on the outcomes
Incomplete outcome data (attrition bias) All outcomes	Low risk	Intention‐to‐treat (ITT) analysis was done on all the patients. Eight patients (2 interferon and 6 observation) died without any follow‐up visits). 144 of 149 participants in the interferon group received at least one injection
Selective reporting (reporting bias)	Unclear risk	Protocol was not available
Other bias	Low risk	No reason to suspect other bias