Lundborg 2004.

Study characteristics
Methods	Study type: RCT Follow‐up: 60 months
Participants	Participants: 30 participants (17 intervention, 13 control) Injury: < 48 hours following injury, complete transection of the median or ulnar nerve at wrist or distal forearm (< 10 cm from the wrist) Age range (years): 12–72 Sex: 4 female, 26 male
Interventions	Intervention: silicone tube (17 nerve repairs in 17 participants) Control: epineural end‐to‐end suturing (13 nerve repairs in 13 participants)
Outcomes	Outcomes measured at 3, 6, 12, 24, 36, 48, and 60 months BMRC grading for sensory recovery Sensory and motor neurophysiology RMI
Funding	Supported by grants from the Swedish Research Council, Swedish Brain Foundation, Faculty of Medicine, Lund University
Conflicts of interest	Did not state any conflict of interest.
Notes	17 participants underwent neurophysiological assessment. We requested raw data, which was provided and facilitated meta‐analysis at the 24‐month time point.
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Low risk	Concealment was performed with sealed envelopes. It is uncertain at what point this was opened; however, all surgeries were performed within the first 48 hours following injury.
Random sequence generation (selection bias)	Unclear risk	Detail of sequence generation not provided.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	It is unclear if participants were blinded.
Blinding of outcome assessment (detection bias) All outcomes	High risk	The examiner was actively blinded during the first follow‐up year; however, due to small‐study size and close follow‐up, blinding was broken by 5‐year follow‐up.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Only 2/30 participants failed to make the 5‐year follow‐up, 1 from the conduit repair and 1 from the standard repair group. All analysis was performed as intention‐to‐treat and there were no deviations from random allocation.
Selective reporting (reporting bias)	Low risk	Results for all expected outcomes were reported.
Other bias	Low risk	No other specific areas of risk of bias.