Ease 2011.

Methods	Randomized clinical trial. 2:1 block randomizations. Allocation concealment was maintained by working with two separate study groups. Follow‐up until 12 months.
Participants	Baseline Age: treatment 64 years versus control 64 years Participants: treatment n = 208 versus control n = 107 % female: 49% Disease distribution: homogenous Baseline score on outcomes: Mean FEV1 % predicted (SD): treatment 23.2% (6.1) versus control 23.6% (7.2) Mean QoL in units total score on SGRQ (SD): treatment 56.6 units (12.9) versus control 58.04 units (13.25) Mean RV % predicted (SD): treatment 244.1 (52.8) versus control 248.5 (51.4) Mean TLC in liter (SD): treatment 7.64 L (1.56) versus control 7.70 L (1.54) Mean DLCO % predicted (SD): treatment 30.6% (11.4) versus control 28.4% (51.4) Mean PaO2: not reported Mean PaCO2: not reported Mean 6MWD in meters (SD): treatment 302 m (88) versus control 297 m (85)
Interventions	Intervention group receive stent placement while control group received sham bronchoscopy.
Outcomes	‐ Forced expiratory volume in one second (FEV1) ‐ Modified medical research council dyspnoea scale (mMRC) ‐ Residual Volume (RV) ‐ Forced vital capacity (FVC) ‐ St. George’s Respiratory Questionnaire (SGRQ) ‐ 6‐minute walk test (6MWD) ‐ Cycle ergometry.
Notes	Funded by Broncus Technologies
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"randomization by independent, automated, internet‐based service (Advance Research Associates, Mountain View, CA, USA), with a permuted block size of six and sequential assignment, stratified by investigational site"
Allocation concealment (selection bias)	Low risk	"To maintain the study blind, investigators were divided into team A (masked), which completed pre‐procedure and post‐procedure assessments, and team B (unmasked), which only did bronchoscopies without further interaction with patients. We communicated randomisation assignments to members of team B only"
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Involved sham procedure so participants were blinded. Not possible to blind the proceduralist
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Outcome assessment was blinded
Incomplete outcome data (attrition bias) All outcomes	Low risk	Attrition reported: balanced between groups
Selective reporting (reporting bias)	Low risk	Protocol published
Other bias	High risk	"Funder was responsible for trial design and coordination and data analysis. The corresponding author and writing committee had full access to all data and had final responsibility for the decision to submit for publication"