Nabhan 2005.

Methods	RCT
Participants	66 people (mean age 52 years, SD 12; 38 males, 28 females) with clinical and electrophysiological evidence of ulnar nerve neuropathy Exclusion criteria: previous traumas to the elbow causing deformity or distortion of the cubital tunnel, as well as recurrent cubital tunnel syndrome after previous surgery
Interventions	Simple decompression (32 participants), decompression and anterior subcutaneous transposition (34 participants)
Outcomes	Clinical outcomes: Yale Sensory Scale MRC scale VAS Electrophysiological outcome: motor nerve conduction velocity
Conflicts of interest	No information provided.
Study funding	No information provided.
Notes	Operations performed between August 2001 and October 2003. Single centre in Germany. Follow‐up examinations at 3 and 9 months after surgery. The sample size was not calculated. Only people with severe disease were included in the study. The authors do not specify if the study was designed to be a non‐inferiority or a superiority trial.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Randomisation was carried out by drawing cards in sealed envelopes"
Allocation concealment (selection bias)	Low risk	Quote: "Randomisation was carried out by drawing cards in sealed envelopes"
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not specified.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Quote: "All patients underwent nerve conduction velocity studies pre‐operatively by two blinded neurophysiologists according to a standard protocol" Comment: It is not specified if the postoperative evaluation was performed by blinded examiners.
Incomplete outcome data (attrition bias) Clinical or neurophysiological outcome	Low risk	No participant lost to follow‐up.
Selective reporting (reporting bias)	Low risk	Results from all the outcome measures are reported.
Other bias	High risk	The outcome measures used to evaluate clinical improvement in terms of sensation and motor strength may have a low sensitivity. The sample size was not calculated. The authors do not specify if the study was designed to be a non‐inferiority or a superiority trial.