Onishi 2000.

Methods	RCT 1988 to 1998
Participants	49 patients Stage IIb to IV
Interventions	Radiotherapy versus concomitant chemoradiotherapy (cisplatin or carboplatin)
Outcomes	Survival, disease‐free survival, local and distant recurrence, acute toxicity, late toxicity
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Data checks on IPD provided suggest adequate sequence generation
Allocation concealment (selection bias)	Low risk	Sealed envelope
Blinding (performance bias and detection bias) All outcomes	High risk	Trial was not blinded due to nature of treatment interventions
Incomplete outcome data (attrition bias) All outcomes	Low risk	IPD provided for all outcomes. NB. Substantial proportion of data missing for late toxicity outcomes
Selective reporting (reporting bias)	Low risk	N/A (IPD supplied for all outcomes)
Other bias	Low risk	Data checks on IPD provided suggest study is free of follow‐up bias