Abdellaoui 2011.

Methods	Randomised controlled trial
Participants	17 participants were enrolled. All participants had been admitted to the ICU with an exacerbation of their disease. 10 were allocated to the intervention group of whom 9 completed the study (7 men, median FEV1 % predicted = 25 (IQR 17 to 41) %, median age = 59 (IQR 57 to 69) yr). 7 were allocated to the control group of whom 6 completed the study (6 men, median FEV1 % predicted = 15 (IQR 10 to 27) %, median age = 67 (IQR 59 to 72) yr).
Interventions	Both groups received education (once per week) and daily active‐passive mobilisation. Intervention: bilateral electrical stimulation of hamstrings and quadriceps using biphasic symmetric, constant current impulses with a pulse width of 400 µs and a frequency of 35 Hz for 1 hour per day, 5 days per week for 6 weeks. Intensity was set at the maximum that could be tolerated for each participant. Control: sham stimulation using identical stimulation parameters, except the stimulation did not cause contractions that were visible or palpable.
Outcomes	Quadriceps strength was measured (in kg) during a maximum voluntary contraction using a dynamometer Exercise capacity via the 6MWT Functional limitation resulting from dyspnoea via the MRC scale Muscle oxidation and fibre typology via biopsy analysis
Notes	Supported by patients' association APARD grant. Two study investigators were supported by a CIFRE grant
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "randomization was performed in block sizes of 5." Quote: "patients were randomly assigned to sham or NMES training." Randomisation sequence developed using a computer (information from authors)
Allocation concealment (selection bias)	Low risk	Quote: "….using blinded sealed envelopes prepared by an independent secretary."
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "patients were blinded to the intervention groups." Quote: "the sham group had weekly therapeutic education sessions, daily active‐passive mobilisation and sham electrostimulation." Although it was unlikely that the investigators administering the electrical stimulation (and sham intervention) were blinded to group allocation, the risk of bias from this was low.
Blinding of outcome assessment (detection bias) All outcomes	High risk	Quote: "tests were performed by researchers who were not blinded to the groups." This was unlikely to have affected outcomes related to muscle oxidative stress and structure, but may have affected measures of muscle strength, exercise capacity and functional limitation resulting from dyspnoea.
Incomplete outcome data (attrition bias) All outcomes	Low risk	1 participant withdrew in each group
Selective reporting (reporting bias)	Low risk	Generally reported as per protocol (except change in primary outcome)
Other bias	High risk	Of the 15 participants who completed the study, 13 were men.