NOA‐04 2009.

Study characteristics
Methods	Randomized controlled trial
Participants	274 AO, AOA and AA 3 of 4 anaplastic features
Interventions	Surgery + RT and temozolomide vs. PCV at progression vs. surgery + temozolomide vs. PCV and RT at progression
Outcomes	Time from operation to treatment failure Overall survival Progression‐free survival Toxicity
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: ''Patients were randomly assigned.'' Comment: probably done.
Allocation concealment (selection bias)	Unclear risk	Quote: ''Baseline characteristics between treatment groups were well balanced.'' Comment: no indication of stratification, but baseline characteristics indeed well balanced between treatment groups.
Blinding (performance bias and detection bias) All outcomes	High risk	Not blinded.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No mention of loss to follow‐up.
Selective reporting (reporting bias)	Low risk	Outcomes reported adequately.