Alberts 2006.

Methods	Randomised controlled trial Trial duration: 11 years, from March 1988 to June 1999 Trial location: USA ‐ 66 participants from South West Oncology Group (SWOG) and 4 from Gynecologic Oncology Group (GOG)
Participants	Number of participants: 70 randomised (35 treatment group, 35 observation alone) Inclusion criteria: Histologically proven advanced (stage II or III) ovarian cancer 120 days or less elapsed between completion of chemotherapy and second‐look surgery South West Oncology Group performance status of 0‐2 White blood cell (WBC) ≥3500μl, platelet count ≥100,000/μl, adequate renal and hepatic function Patent intraperitoneal space at the time of second‐look surgery Registered no later than 42 days following second‐look surgery Exclusion criteria: not specified
Interventions	Intervention: Alpha‐interferon (IFNα‐26, Schering‐Plough Kenilworth, NJ) in weekly doses of 50x106 IU (for 6 doses) Control: observation alone
Outcomes	Overall survival Progression free survival, definition was not specified Adverse events: abdominal pain/cramping, alopecia, anemia, arthralgia, catheter‐related infection, diarrhea without colostomy, dizziness/lightheadedness, dyspenia, fatigue/malaise/lethargy, fever without neutropenia, fever, flu‐like symptoms, headache, hypotension, leukopenia, local injection site reaction, myalgia/ arthralgia, nausea, neutropenia/granulocytopenia, pain, rigors/chills, SGOT (AST) increase, sensory neuropathy, urinary tract infection, vomiting
Notes	Ethics approval: the trial received local institutional review board (IRB) review and approval according to institutional guidelines Informed consent: IRB approved consent forms were signed by the patients Funding: source of funding/conflict of interest not declared Correspondence with authors: dalberts@azcc.arizona.edu on the 3rd July 2012
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	It is reported that patients were randomised but the method of randomisation is not described
Allocation concealment (selection bias)	Unclear risk	Not reported on
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not reported on. Control group was merely observed
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not described
Incomplete outcome data (attrition bias) All outcomes	Low risk	Loss to follow‐up was minimal and similar in both groups (3/35 intervention, 0/35 control)
Selective reporting (reporting bias)	Unclear risk	Protocol was not obtained
Other bias	Unclear risk	Trial stopped early due to poor accrual of patients