Sorensen 1984.

Methods	Single centre RCT comparing talc instillation with pleural drainage only in the treatment of MPE (Denmark)
Participants	Inclusion: histologically proven MPE (all cell types) causing respiratory distress, which is progressive and resistant to conventional therapy Exclusion: failure of the underlying lung to totally re‐expand within 72 hours of the thoracoscopy 31 participants randomised
Interventions	All participants underwent thoracoscopy, during which multiple biopsies were taken and a drain inserted. Suction applied until complete lung re‐expansion Drainage alone group: constant suction for 72 hours after complete lung re‐expansion. Then, drain removed Talc and drainage group: 10 g sterile talc in 250 ml saline instilled through chest tube and clamped for two hours. Then suction applied for 72 hours and the drain was removed
Outcomes	Fluid re‐accumulation on CXR every month for three months
Notes	People with trapped lung excluded from trial entry No data provided on whether treatment arms well matched at baseline Power calculation performed Unclear if adverse events reported for all participants or only those who completed the follow up Pleurodesis defined using radiology only Included in network meta‐analysis for pleurodesis efficacy
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not stated
Allocation concealment (selection bias)	Low risk	"Closed envelope system"
Blinding of participants and personnel (performance bias) All outcomes	High risk	Unable to blind due to nature of the interventions (pleural drainage alone, or with talc administration)
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Adverse event reporting could be biased by lack of blinding. Not stated if CXR interpretation was blinded
Incomplete outcome data (attrition bias) All outcomes	High risk	10/31 (32%) excluded from primary analysis (but well balanced between the two treatment arms)
Selective reporting (reporting bias)	Low risk	No comment on mortality or survival, but an old study and not stated as an outcome measure in the paper
Other bias	Low risk	No other biases identified