Buckley 2002.

Study characteristics
Methods	RCT, parallel design, 2‐armed trial
Participants	Total number of randomised participants: 424 (471 fractures) Source population: initially 7 centres (14 surgeons) in Canada recruited, but data from only 4 (6 surgeons) were included as they complied with the requirement of a minimum of 20 participants followed up for at least 2 years from each participating surgeon Inclusion criteria: intra‐articular fracture, displaced > 2 mm on CT scan Exclusion criteria: medical contraindication to surgery; previous calcaneal injury; coexistent foot injury; head injury; injury that had occurred more than 14 days before presentation Overall baseline characteristics Age, mean (SD): 40 (± 11) years Sex (M/F): 381/43 Bilateral fractures: no information on numbers by treatment arm; however, the lead author reported that 47/310 (15%) participants recruited from 1 centre had bilateral fracture Workers' compensation: 157/424 (37%) work‐related injury Baseline characteristics for surgical group Age, mean: 41 years Baseline characteristics for non‐surgical group Age, mean: 39 years
Interventions	Surgical group Number randomised: 206 (249 fractures) Losses (with reasons): 45 (35 lost to follow‐up, 7 fused, 3 died) Number analysed: for complications: 218 (262 fractures); for all other outcomes: 206* Treatment description: ORIF involving extended lateral approach, use of plate, screw, or wire fixation. Autografting left to surgeon discretion. Physiotherapy started after 6 weeks for all participants. Non‐surgical group Number randomised: 218 (262 fractures) Losses (with reasons): 70 (29 lost to follow‐up, 37 fused, 4 died) Number analysed: for complications: 206 (249 fractures); for all other outcomes: 218* Treatment description: ice, elevation, rest. Physiotherapy started after 6 weeks for all participants. *Flow of participant information is not clearly reported in the text. Although 64 participants were lost to follow‐up, complication data for these participants were tracked by nurses. Study authors report "complete case" data for 242 participants for function and HRQoL, but they do not describe how they accounted for lost participants in these data.
Outcomes	Timing of assessments: 2 to 4 weeks, 6, 12, 26, 52 weeks, and 2 (minimum) to 8 years (maximum) Outcomes reported in review: quality of life (SF‐36), disease‐specific scale (VAS) (primary outcomes); Böhler's angle, postoperative complications (treatment failure/subtalar arthrodesis) Note: we did not report data for Böhler angle because we could not determine whether the data were between time points (before and after surgery) or between intervention groups (surgical and non‐surgical) or were mean postoperative data.
Notes	Study dates: April 1991 to December 1997 Funding sources: not reported Declarations of interest: not reported Notes: Sample size varied across publications. Contact was made (JB) with the lead study author (email 20 November 2011), and data were requested (SD values for VAS, SF‐36 scores and Böhler angles, clarification about sample size differences between different publications from 2 to 8 years' follow‐up). Lead study author responded (25 November 2011), but trial data were stored on floppy discs and unable to access for conversion to CD format. Original paper records were archived and held for 10 years, but not possible to access without extra time/resources. Of the 206 surgical procedures, 73% were conducted by lead study author. Data reported across multiple abstracts and publications with subgroup analyses conducted.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Random number tables used after eligible for entry into study. Random numbers generated at the site of the Principal Investigator.
Allocation concealment (selection bias)	Low risk	Central administrative site sent random number assignments to study centres.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Due to nature of intervention, treating surgeons and participants were not blinded to the intervention
Blinding of outcome assessment (detection bias) All outcomes	High risk	Outcome assessment by postal questionnaire sent to study participants (primary outcome of quality of life). Assessment of CT scans to assess quality of reduction was conducted by lead study author who was not blinded.
Incomplete outcome data (attrition bias) All outcomes	High risk	309/424 (73%) followed up for minimum of 2 years, maximum of 8 years (mean 3 years). Response rate to questionnaire is not clearly reported. A later publication by O'Brien 2004 stated that 319 participants completed the RCT at 2 to 8 years but reported different SF‐36 values from the main paper (Buckley 2002). We also noted exclusion of data from 3 centres. The derivation of the data for the primary outcomes so that it is from the 'complete study group' is not shown. Study report states that intention‐to‐treat analysis was conducted. However, 44 cases (44/424 (10%)) who went on to have subtalar fusion were excluded from analyses.
Selective reporting (reporting bias)	Unclear risk	No protocol or clinical trials registration. It is not feasible to effectively assess risk of selective reporting bias without these documents.
Other bias	Low risk	We identified no other sources of bias