| Methods |
Randomised, placebo‐controlled cross‐over study |
| Participants |
5 children with SLSJ‐COX deficiency |
| Interventions |
Dimethylglycine or placebo (50 mg/kg/day if < 33 kg, 5 g/day if > 33 kg). 2‐week washout |
| Outcomes |
Oxygen consumption (VO2) by indirect calorimetry, venous lactate, pyruvate, bicarbonate and pH |
| Notes |
No significant effect |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Low risk |
"The order of administration of placebo and DMG was randomized by using a one‐block sequence generated from a random number table." |
| Allocation concealment (selection bias) |
Unclear risk |
Method of allocation not specified |
| Incomplete outcome data (attrition bias)
All outcomes |
Low risk |
All participants completed all outcome assessments |
| Selective reporting (reporting bias) |
Low risk |
All outcome measures in methods section were reported in results section |
| Other bias |
Low risk |
None identified |
| Blinding of participants and personnel (performance bias)
All outcomes |
Low risk |
"Capsules containing placebo or DMG were indistinguishable." This was a double‐blind cross‐over trial, involved dieticians were also blinded |
| Blinding of outcome assessment (detection bias)
All outcomes |
Low risk |
Participants were randomly assigned to start in either the DMG or placebo arm. |
