EORTC 08861.

Methods	1986 to 1990 RCT
Participants	106 patients Stages II, III Trial data used in subgroup analyses for sex, age, histology, stage and nodal status
Interventions	Surgery + radiotherapy vs surgery alone RT details 56 Gy in 28 fractions in 5.5 weeks Prescription technique: central axis, at the midplane Machine used: linac Average field size (cm): 15 × 10 Clinical target volume: hilum, mediastinum Technique: composite plans
Outcomes	Survival
Notes	Unpublished trial
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Comment: unpublished trial; checks run on IPD suggest adequate sequence generation
Allocation concealment (selection bias)	Low risk	Comment: unpublished, insufficient information provided, but collection of IPD and correspondence with those who supplied the data reassured that data were adequate
Blinding (performance bias and detection bias) All outcomes	Low risk	Comment: trial not blinded owing to the nature of the intervention; outcome not likely influenced by lack of blinding
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: individual participant data obtained and checked for all outcomes
Selective reporting (reporting bias)	Low risk	Comment: individual participant data obtained and checked for all outcomes
Other bias	Low risk	Comment: study apparently free of other sources of bias