Burke 1994.

Methods	Double‐blind quasi‐randomised controlled trial Blinded subjects and assessors* Ethics approval and informed consent obtained Quasi‐randomisation occurred at the level of wrists, where participants with bilateral CTS received a different intervention for each affected wrist.
Participants	Total N = 59 (90 wrists) randomised Group 1 N = 45 wrists randomised Group 2 N = 45 wrists randomised Gender of participants not reported. Age of participants not reported. Inclusion criteria: 1. Clinical diagnosis of CTS (hypoaesthesia or paraesthesiae in median nerve distribution, weakness or atrophy in abductor pollicis brevis or opponens pollicis) Exclusion criteria: 1. History of CTR surgery 2. Injection at wrist 3. Previous splint use
Interventions	Group 1: Wrist splint in neutral for two months Group 2: Wrist splint in 20° extension for two months Wearing regimen (day or night) was not controlled, though researchers emphasised to participants nightly use of splints.
Outcomes	Outcome assessed at two weeks and two months** 1. Symptom relief*** (overall, nocturnal, daytime) assessed using ordinal scale (1 = not at all, 2 = a little, 3 = a lot, 4 = completely) 2. Compliance**** (wore splint every night, most nights, some nights, never) 3. Adverse effects (any difficulty with splints)
Notes	Age and sex of participants not reported *Confirmed with author in personal communication **No data for any of the outcomes at two months were reported ***Dichotomised by trialists for analysis into 'a lot/complete relief' and 'none/little relief' ****Not a pre‐specified outcome of interest to this review Analysis was undertaken at the wrist‐level for all outcomes, though some participants in each group had bilateral CTS. Bilateral cases had a different intervention applied to each wrist. The trialists did not report how the correlation between both wrists was accounted for in the analysis, and attempts to clarify this information from the trialists were unsuccessful. Therefore, it is not clear whether a unit of analysis error occurred. No attempt was made to adjust outcome data.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Quote: "Splinting was completed by alternating between extension and neutral. The order of splinting was dominate then non‐dominant hand. Thus, if the next splint on the alternating list was for neutral, the dominant hand would then receive the extension splint".       Comment: A non‐random sequence (alternation) was used.
Allocation concealment (selection bias)	High risk	Comment: Alternate allocation was used therefore trial personnel and participants could predict the order of group assignments.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "Both splints were attached in the same way, and patients were not told of the difference in angle. No patients expressed an awareness of a difference between the two splints". Comment: Participants were probably blind to group assignments.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "Both splints were attached in the same way, and patients were not told of the difference in angle. No patients expressed an awareness of a difference between the two splints". Comment: All outcomes (symptom relief; overall, nighttime, daytime) were self‐reported by participants who were blinded to group assignments
Incomplete outcome data (attrition bias) 3 months or less	High risk	Comment: Data missing for daytime and nighttime symptom relief assessed at two weeks. For daytime relief, 5 wrists were missing from the neutral splint group and 23 wrists were missing from the extension splint group. For nighttime relief, 3 wrists were missing from the neutral splint group and 18 wrists were missing from the extension splint group. There was a disproportionate number of wrists missing from the extension splint group compared with the neutral splint group and no explanation for missing data was provided. Results for symptom relief at daytime and nighttime could have been biased in favour of neutral splints.
Selective reporting (reporting bias)	High risk	Comment: There was selective reporting of outcomes assessed at two weeks due to incomplete data for outcomes assessed at two months. Nighttime and daytime compliance were measured but not reported. Participants were instructed to return to the clinic if they had any difficulty with the splints however, it is not stated whether this occurred for any cases.
Other bias	Low risk	Comment: No other sources of bias identified.