Umsawasdi 1984.

Methods	Randomised 2‐arm trial. Radionuclide/CT brain if neurological symptoms developed. Incidence, time to brain metastases and survival reported.
Participants	97 patients with locally advanced NSCLC(13% stage I/II, 87% stage III); any age; any performance status. Thoracic treatment not clearly described.
Interventions	30Gy/10F/2 weeks PCI versus observation.
Outcomes	Significant reduction in the incidence of brain metastases with PCI (4% versus 27%, p=0.02). PCI significantly prolonged time to brain metastases (50.5 weeks versus 23 weeks, p=0.02). No significant difference in survival.
Notes	100 patients randomised. 3 exclusions (all accounted for). Randomization method not stated. Thoracic treatment not fully described. Follow‐up protocol not stated. No formal assessment of toxicity or QOL.
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Unclear risk	Quote: ‘We evaluated the clinical impact of elective brain irradiation (EBI) in a prospective randomised study’  No mention of randomisation method.
Allocation concealment?	Unclear risk	Quote: Insufficient information. However, the allocation of treatment appears to be so complicated that it is unlikely to be without bias.
Incomplete outcome data addressed? All outcomes	High risk	Quote: ‘Three of 49 patients who were randomised to receive EBI were excluded from the analysis because they did not receive EBI due to a scheduling error.  One of these patients had CNS metastasis during the course of their treatment’ The exclusion from analysis of these patients in the treatment group (especially of the patient who developed CNS metastasis, a primary outcome of this trial) means that the trial cannot be free of bias.