Arinci Incel 2005.

Methods	Randomised controlled trial No blinding reported Ethics approval and informed consent obtained Randomisation occurred at the level of participants, where participants with bilateral CTS received the same intervention for both affected wrists.
Participants	Total N = 70 (115 wrists) randomised Intervention group N = 35 (60 wrists) randomised Control group N = 35 (55 wrists) randomised 0 males, 70 females Mean ± SD age: Intervention group: 49.94 ± 8.12 years Control group: 49.82 ± 7.01 years Inclusion criteria: 1. Diagnosis of CTS confirmed by electrodiagnostic studies performed on a Medelec Synergy v2.0; criteria were median sensory distal latency greater than 3.6 msec; prolonged in the wrist to palm segment, with or without prolongation of the distal motor latency by using supramaximal stimulation and surface electrodes. Exclusion criteria: 1. Concomitant polyneuropathy; 2. Neurologic or inflammatory arthritis conditions; 3. History of upper extremity fracture; 4. Previous use of gabapentin for any other reason.
Interventions	Intervention: gabapentin 1800 and 2400 mg/day, which was titrated progressively: 300 mg at bedtime on day 1, 300 mg twice on day 2 and 300 mg three times a day on day 3. The dosage was individualised for each participant between 1800 and 2400 mg as recommended. Duration of this treatment was 6 months. Control: splint‐exercise: participants were instructed to wear a neutral, volar wrist splint at night and during the day as much as possible for 6 months. Nerve and tendon gliding exercises as described by Tetton and Hunter were ordered to both groups. A brochure demonstrating hand positions of these exercises was given to participants. The exercises were repeated twice daily, 10 times at each session.
Outcomes	Outcomes assessed at baseline and at the end of 6 months of treatment:*  1. Grip strength (kg) using a Jamar hand dynamometer. The mean of 3 attempts was reported.   2. Pinch strength (kg) using a pinch meter. The mean of 3 attempts was reported.   3. Symptoms using carpal tunnel questionnaire (rates 11 items on ordinal scale 1: no difficulty with the activity, to 5: cannot perform the activity at all) 4. Hand function using carpal tunnel questionnaire (rates 8 items on ordinal scale 1: no difficulty with the activity, to 5: cannot perform the activity at all) 5. Pain using a 10 cm VAS.  6. Quality of life using the SF‐36. The units of measurement (i.e. scores calculated) for this outcome were not reported by the authors.   7. Adverse events: no reporting on how these events were recorded and how frequently this was done.
Notes	* Analysis was undertaken at the wrist‐level for all outcomes, though some participants in each group had bilateral CTS. Bilateral cases had the same intervention applied to each wrist. The trialists reported (via personal communication) that the correlation between both wrists was not accounted for in the analysis. Therefore, a unit of analysis error occurred. Numerical data were only reported for the gabapentin group at the end of six months of treatment, so no data from this study were entered into RevMan.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "Participants were randomised to 2 groups: splint‐exercise group and gabapentin‐exercise groups with 35 patients in each." Comment: Not enough information to determine the adequacy of the sequence generation
Allocation concealment (selection bias)	Unclear risk	Quote: "Participants were randomised to 2 groups: splint‐exercise group and gabapentin‐exercise groups with 35 patients in each." Comment: not enough information to determine whether the allocation sequence was adequately concealed until interventions were assigned
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Comment: not reported, but due to the nature of the interventions (splint vs oral drug), it is unlikely that participants were not aware of which treatment they were allocated to
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Comment: not reported, and it would have been possible to blind the outcome assessors of the objective outcomes (grip and pinch strength)
Incomplete outcome data (attrition bias) 3 months or less	Unclear risk	Quote: "Seventy patients with CTS were enrolled in the study." Comment: the authors do not report that there were no withdrawals or losses to follow‐up, and do not indicate whether the data obtained at the end of 6 months treatment were based on the complete randomised sample
Selective reporting (reporting bias)	High risk	Comment: the authors only reported data at the end of 6 months of treatment for the gabapentin plus exercises group; the results for the splint group are only reported descriptively (i.e. indicating whether a 'significant' or 'non‐significant' difference existed between groups)
Other bias	Low risk	Comment: No other sources of bias identified.