Leroi 2005#.

Methods	Randomised crossover trial Blinding: participant and investigator. Sequence generation by random number table. Follow‐up: 3 months Setting: multicentre, France Intention‐to‐treat analysis: no
Participants	Enrolled: 34 Median age (range): 57 (33 to 73) Gender: male (3); female (31). Duration of symptoms: < 1 yr (12); 1 to 5 years (12); 5 to 10 years (4); > 10 years (6) Received permanent implant: 27 Lost to follow‐up: 3 Inclusion criteria: faecal incontinence to solid or liquid stool or incapacitating urgency; failed conservative treatment; demonstrable unilateral bulbo‐ (or clitorido‐) cavernosus reflex; informed consent given. Participants with external anal sphincter damage on ultrasound were included in the study if the defect was not considered to be the main cause of faecal incontinence (i.e. limited defect, ≥ than 30° or limited to one part, superficial, middle, or deep part of the external anal sphincter). Exclusion criteria: extensive external anal sphincter defect (defect that was considered to be the main cause of faecal incontinence).
Interventions	Before permanent implantation, participants underwent temporary stimulation, either percutaneously‐placed test stimulation lead (Medtronic InterStim 3057) or permanent quadripolar lead (model 3093). Both types of leads were connected to an external pulse generator (model 3625). All participants were tested for 8 to 15 days. For permanent implantation, participants with temporary test stimulation lead underwent simultaneous implantation of the quadripolar lead and the pulse generator; those with a lead already in place underwent removal of the percutaneous extension (model 3095) before placement of the pulse generator (model 3023) subcutaneously, below the superficial fascia, in the upper parts of buttocks ipsilateral to the permanent electrode. The lead contained four contact electrodes. The electrode combination which allowed the participant to have the best perception of the perineum muscle and anal sphincter contraction was chosen for permanent stimulation. Stimulation was continuous with a pulse width of 210 microseconds, a frequency of 14 pulses per second, and a current amplitude adapted to the participant's perception of perineal and anal sphincter muscle contraction. The stimulator was left on during defaecation and urinary voiding. After a 1‐ to 3‐month optimisation 'on' phase, participants were randomised to: A Intervention: stimulation 'on' for 1 month or B Control: stimulation 'off' for 1 month, then crossed over to the alternative. No treatment‐free interval At the end of the second month, the preferred period ('on' or 'off') was continued for a further 3 months: if neither was preferred, the stimulator was turned on.
Outcomes	Episodes of faecal incontinence; faecal urgency; delay in postponing defaecation; bowel movements; severity of incontinence; quality of life; anal manometry.
Notes	Severity of incontinence was graded by the Cleveland Clinic Incontinence Scoring System. The score ranged from 0 (normal continence) to 20 (maximum incontinence). Quality of life was assessed with the French version of the American Society of Colon and Rectal Surgeons' Fecal Incontinence Quality of Life Questionnaire (FIQL). In the questionnaire, four separate QOL domains were explored: lifestyle; coping/behaviour; depression/self‐perception; and embarrassment.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Random number tables.
Allocation concealment (selection bias)	Unclear risk	Unclear 'Randomised crossover trial'.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Participants were blinded to treatment allocated.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Personnel assessing outcome were blinded.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Out of the 34 participants enrolled, 10 prematurely discontinued. The reasons for discontinuation were device‐related adverse events (n = 4), protocol violation (n = 3), insufficient therapeutic response (n = 1), no return to follow‐up (n = 1), and adverse event (stroke) not related to SNS (n = 1).
Selective reporting (reporting bias)	Low risk	All outcomes reported.
Other bias	Low risk	None identified