Nield 2012.

Study characteristics
Methods	Study design: single‐centre, open‐label, parallel randomised controlled trial in the USA Duration: 12 weeks Setting: secondary care
Participants	Population: 22 adults recruited from West Los Angeles VA Healthcare Center Baseline characteristics: mean age 65 years, male: 100%, current smokers (n): 11/22, FEV1 (% predicted): 56, concomitant medications: not reported Inclusion criteria: age > 45 years; FEV1/FVC < 70%, predicted FEV1/FVC < 80% with no reversibility after inhaled bronchodilator, SOB score ≥ 3 when walking (MMRC chronic dyspnoea questionnaire) Exclusion criteria: hospital admission in last four weeks, change of bronchodilator therapy in last two weeks
Interventions	Measurements taken at baseline, 4 weeks and at a 12 week follow‐up Treatment arms: Ten minute PLB education session from a healthcare professional, an education pack including a logbook, then also weekly telehealth reinforcement sessions for 4 weeks Ten minute PLB education session from a healthcare professional, an education pack including a logbook
Outcomes	Lung function VAS Borg category‐ratio scale SOBQ
Notes	Funding: Breathe California of Los Angeles County, National Institutes of Health Other identifiers: NCT01161290
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Reported as randomised, no further information about the process
Allocation concealment (selection bias)	Unclear risk	Staff member who allocated the numbers was not related to the study, but it was unclear if the numbers were concealed or not
Blinding of participants and personnel (performance bias) All outcomes	High risk	No further information, but blinding would not be possible due to the nature of the treatment
Blinding of outcome assessment (detection bias) All outcomes	High risk	No further information, but subjective outcomes likely to be high risk of bias as these are self‐reported assessments by participants
Incomplete outcome data (attrition bias) All outcomes	Low risk	Similar number of participants lost to follow‐up, 2 more in the intervention group compared to the control group
Selective reporting (reporting bias)	High risk	SDs were not reported for outcomes assessed, so calculated from SE. The results for Borg scale was not reported, and nether was the shortness of breath questionnaire. No registration details found online
Other bias	Low risk	None identified