Griffin 2014.

Study characteristics
Methods	RCT, parallel design, pragmatic, 2‐armed trial
Participants	Total number of randomised participants: 151 Source population: multicentre; participants recruited from 22 UK hospitals; all centres were regional referral centres for calcaneal fractures. Surgeons were "recognised as specialists in the treatment of these injuries". Inclusion criteria: intra‐articular fracture, displaced > 2 mm, > 18 years of age Exclusion criteria: gross deformity of the hindfoot, other serious leg injuries sufficient to affect the outcome at 2 years, not fit for surgery, peripheral vascular disease Overall baseline characteristics Sex (M/F): 127/24 Age, mean (range): 46.5 (18 to 80) years Bilateral fractures: included, but no data reported. Outcomes were reported for the more severely injured side for bilateral fractures. Baseline characteristics for surgical group Sex (M/F): 64/9 Age, mean (SD): 44.8 (± 14.8) years BMI, mean (SD): 25.4 (± 5.1) kg/m2 Smokers, n (%): 37 (51) Diabetes, n (%): 1 (1) Type of fracture (Sanders II/III/IV), n (%): 35 (49)/27 (38)/9 (13) Baseline characteristics for non‐surgical group Sex (M/F): 63/15 Age, mean (SD): 48.2 (± 16.5) years BMI, mean (SD): 25.3 (± 3.9) kg/m2 Smokers, n (%): 44 (56) Diabetes, n (%): 3 (4); (1 participant with unknown diabetes status) Type of fracture (Sanders II/III/IV), n (%): 35 (46)/30 (39)/11 (15)
Interventions	Surgical group Number randomised: 73; 5 received non‐operative care (changed their minds after randomisation = 2; declined surgery during wait for operation = 1; declined surgery after later discussion with surgeons = 2) Losses (with reasons): 4 (died = 1; withdrew = 1; lost to follow‐up = 2) Number analysed: 69 Treatment description: ORIF within 3 weeks, involving extensile lateral approach, use of neutralisation plates or plates to the lateral wall of the calcaneus, interfragmentary screws Non‐surgical group Number randomised: 78; 3 received operative care (all changed their minds after randomisation) Losses (with reasons): 4 (died = 2; withdrew = 1; lost to follow‐up = 1) Number analysed: 74 Treatment description: early gentle mobilisation with the fitting of a removable splint. Mobilised and non‐weight‐bearing for 6 weeks, followed by 6 weeks partial weight‐bearing
Outcomes	Timing of assessments: 6, 12, 18, 24 months Outcomes reported in review: Kerr‐Atkin's score, function (AOFAS), quality of life (SF‐36 and EQ‐5D), postoperative complications, reoperation (removal of metal implants and subtalar arthrodesis), return to work Other outcomes: heel width, walking speed, movement (dorsiflexion, plantar, eversion, inversion) and gait symmetry indices Note: study conducted subgroup analysis according to Sanders classification and sex
Notes	Study dates: 2007 to 2009 Funding sources: Arthritis Research UK Declarations of interest: study authors declared no conflicts of interest Notes: Dr Nicholas Parsons and Mr Damian Griffin were contacted (JB) by email 23 October 2015 for clarification regarding allocation concealment. The lead senior statistician on the study (NP) clarified that they had used a central randomisation service by telephone and confirmed allocation concealment.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Participants were randomised 1:1 to receive operative and non‐operative treatment using a minimisation algorithm". Comment: randomisation was by participant and individuals with bilateral fractures received the same treatment on both sides. Although sequence generation was adequate for this study, we note that a large number of eligible participants did not consent to study participation because of a preference for one treatment over another. We could not rule out the possibility that participants were provided with information from surgeons about their fracture type that influenced their decision to consent.
Allocation concealment (selection bias)	Low risk	Secure telephone randomisation service used managed by an independent clinical trials unit (York, UK).
Blinding of participants and personnel (performance bias) All outcomes	High risk	Due to nature of intervention, treating surgeons and participants were not blinded
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Participant‐reported outcomes were captured by postal questionnaire and because participants were aware of group allocation, detection bias for these outcomes was high risk. The assessment of clinical outcomes at 2 years was performed by a physiotherapist who was unaware of treatment allocation. During clinical examination, thin socks were worn to obscure surgical scars and maintain blinding of the physiotherapist.
Incomplete outcome data (attrition bias) All outcomes	Low risk	143/151 (95%) patients completed follow‐up at 2 years. Reasons for no follow‐up included death (n = 3), participant withdrawal (n = 2) and lost to follow up (n = 3); these losses were balanced between intervention groups.
Selective reporting (reporting bias)	Low risk	Study was prospectively registered in a clinical trials register (ISRCTN37188541). Reported primary and secondary outcomes were consistent with those in the clinical trials register documents.
Other bias	Low risk	We identified no other sources of bias