Silva 2016.

Methods	Randomised controlled cross‐over trial (cross‐over at 2 weeks) Study period: October 2014 to January 2015
Participants	Orthopaedic Institute for Children, Los Angeles, California, USA 27 children with non‐displaced or minimally angulated (< 15 °) fracture of the distal radius Exclusion: skeletally mature patients (closed physis), any associated generalised condition that affected the forearm or wrist range of motion, history of injury or surgery to the affected or contralateral forearm or wrist, open fractures, neurovascular abnormalities or suspicion of a compartment syndrome, or established skin irritating conditions (i.e. eczema) Sex: 15 male (58% of 26) Age: mean 9.4 years, range 6 to 13 years Fracture type: nondisplaced or minimally angulated (< 15 °) fracture of the distal radius (23 buckle and 3 greenstick fractures) Assigned: 12 (+1?) (waterproof cast) / 14 (+1?) (traditional fibreglass cast) (see Notes) Analysed: 12 / 14 (at 2 weeks before cross‐over)
Interventions	At Urgent Care facility, cast applied after radiographs 1. Waterproof cast: below‐elbow cast made of the waterproof hybrid mesh material with a waterproof skin protector. Participants with the waterproof cast were asked to shower and get the waterproof cast as wet as they desired 2. Non‐waterproof cast: below‐elbow cast of traditional fibreglass material with a non‐waterproof lining material. Participants with the traditional cast were asked to keep it dry Participants returned for a clinical and radiological evaluation 1 week after cast application to ensure that no further displacement of the fracture had occurred and to evaluate the overall level of comfort The cross‐over (casts were replaced by the alternative cast) took place at 2 weeks post‐cast application, at which time a new clinical and radiological evaluation was performed. Cast removal was achieved in both groups using a cast saw and standard techniques. No physical therapy was prescribed to any participant. After cast removal (4 weeks), all participants were advised to avoid physical education, contact sports, and strenuous activities until week 8 to avoid refractures
Outcomes	Length of follow‐up: 8 weeks, also 1, 2 and 4 weeks (but only data from the first 2 weeks were evaluated for this review) Function: Activities Scale for Kids – Performance (ASK‐P) (questionnaire) Redisplacement Complications or non‐routine cast changes; skin changes at the time of cast removal Pain: Faces Pain Scale – Revised version Itching (VAS) Participant satisfaction with the treatment at cast removal (survey) Costs (comments)
Funding and declarations of interest	Funding source: not stated Declarations of interest: reported, none
Notes	1 participant was excluded because they sought care at a different facility after the initial cast immobilisation. JE sent an email to Dr Silva 11.04.17 asking: 1. Please could you tell us the mean age, the number of males/females, and the fracture types in each group? Allocated waterproof cast (n = 12). Mean age: ; number of males: ; number of buckle fractures: Allocated non‐waterproof cast (n = 14). Mean age: ; number of males: ; number of buckle fractures: 2. Did you provide any advice on drying the waterproof cast; for example, after showering? 3. Please can you provide the standard deviations for the 2 groups at Week 0‐2 for the following: ‐ Total ASK‐P score. Waterproof cast: ; Nonwaterproof cast: ‐ Pain score. Waterproof cast: ; Nonwaterproof cast: ‐ Itchiness score. Waterproof cast: ; Nonwaterproof cast: ‐ Patient satisfaction. Waterproof cast: ; Nonwaterproof cast: 4. Please could you provide the cost of each type of cast: Waterproof cast (HM cast): Nonwaterproof (Scotchcast): No response received.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: “Randomization was performed using sealed, sequentially numbered envelopes, in which the randomisation sequence was concealed.”
Allocation concealment (selection bias)	Low risk	Quote: “single‐center, randomised, controlled, cross‐over” Quote: “Randomization was performed using sealed, sequentially numbered envelopes, in which the randomisation sequence was concealed” This applied to first 2 weeks; after this treatment was crossed over to the other cast
Blinding of participants and personnel (performance bias) Subjective outcomes	High risk	Blinding of personnel, children or parents not possible
Blinding of participants and personnel (performance bias) Objective outcomes	High risk	Blinding of personnel, children or parents not possible
Blinding of outcome assessment (detection bias) Subjective outcomes	High risk	Participants were not blinded
Blinding of outcome assessment (detection bias) Objective outcomes	Low risk	Quote: "The identification of skin changes was performed by an independent observer, who was unaware of the type of cast that had been removed, by analysis of digital photographs of the front and back of the forearm" No blinding for the other aspects but only 2 weeks data used in the review
Incomplete outcome data (attrition bias) Subjective outcomes	Low risk	1 participant (group not identified) excluded as they sought care elsewhere. Unlikely to have impacted on the results
Incomplete outcome data (attrition bias) Objective outcomes	Low risk	1 participant (group not identified) excluded as they sought care elsewhere. Unlikely to have impacted on the results
Selective reporting (reporting bias)	Unclear risk	Although prospectively registered, the cross‐over study design was inappropriate and has meant that the follow‐up data available for this review was curtailed to 2 weeks
Other bias: major imbalance in baseline characteristics	Unclear risk	Separate data for the 2 initially allocated groups were not reported
Other bias: performance bias	Low risk	Quote: “All casting procedures were performed by the on‐call orthopedic staff member, with the assistance of an experienced cast technician”
Other bias	Unclear risk	The cross‐over design of the trial may have influenced the results, even at 2 weeks