Tasdemir 2015.

Methods	Randomised controlled trial
Participants	34 medically stable participants were enrolled. 17 were allocated to the intervention group and of these, data were available on 13 (11 men, median FEV1 % predicted = 29 (range 16 to 71) %, mean age = 62 (SD 8) yr). 17 were allocated to the control group and of these, data were available on 14 (13 men, median FEV1 % predicted = 42 (range 23 to 66) %, mean age = 63 (SD 8) yr).
Interventions	Participants in both groups completed a pulmonary rehabilitation programme for 2 days per week over 10 weeks. Intervention: NMES of both quadriceps using a symmetric, biphasic constant current impulse with a pulse width of 300 µs, at a frequency of 50 Hz. Duty cycle was 10 s on, 20 s off for 20 min (administered during each pulmonary rehabilitation session). Intensity was titrated to the maximum tolerable. Control: sham stimulation using a similar protocol, except that stimulation frequency was 5 Hz and the intensity was sufficient to cause a visible twitch.
Outcomes	Exercise capacity via the incremental shuttle walk test and the endurance shuttle walk test HRQoL via the SGRQ Quadriceps strength using a 1‐repetition maximum and 30‐s chair up test Quadriceps endurance using a squat test and a 2‐min step in place test Quadriceps fatigue using a visual analogue scale Activities of daily living using the LCADLS Functional limitation resulting from dyspnoea using the MRC Dyspnoea scale Fatigue using the Fatigue Severity Scale Feelings of anxiety and depression using the HADS
Notes	Funding support not stated
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "prospective randomized controlled study" Quote: "using a computer‐generated randomization list"
Allocation concealment (selection bias)	Low risk	Quote: "The randomization sequence was concealed using a sealed envelope."
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Control group received sham intervention. Unlikely that the investigators administering the electrical stimulation were blinded to group allocation, but the risk of bias from this was low.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Quote: "The evaluation team was blinded to the patients' treatment. They were not blinded to the final evaluations, although the psychologist who administered the St. George Respiratory Questionnaire and the Hospital Anxiety and Depression scale was blinded." The physiotherapists involved in collecting all other measures may not have been blinded and this may have affected measures of exercise capacity, quadriceps strength and endurance, dyspnoea, fatigue and activities of daily living
Incomplete outcome data (attrition bias) All outcomes	Low risk	Similar loss to follow‐up in both groups (4 participants in the intervention group and 3 participants in the control group). Reason for loss to follow‐up were similar in both groups.
Selective reporting (reporting bias)	High risk	Reported on several outcomes that were not stated in the study protocol.
Other bias	High risk	Disproportionate number of men