QALS Study Group 2009.
| Methods | An adaptive, two stage, bias‐adjusted, randomized, placebo‐controlled, double‐blind, Phase II study of coenzyme Q10. Coenzyme Q10 1800 mg/day and 2700 mg/day. A total of 185 patients with ALS was studied | |
| Participants | The study was conducted at 19 centres in the USA. Diagnosis was of definite, probable, or laboratory supported probable ALS, sporadic or familial, by El Escorial guidelines | |
| Interventions | The design was innovative, aiming to minimize sample size and length of follow up. In Stage 1, 35 patients were allocated to each of placebo, CoQ10 1800 mg/day and CoQ10 2700 mg/day, for 9 months. The dose of 2700 mg/day had higher efficacy, and was chosen Stage 2. In Stage 2, 40 patients were added to each of the placebo and CoQ10 2700 mg/day groups, and studied for a further 9 months | |
| Outcomes | The primary outcome was decline in the ALS Functional Rating Scale‐revised (ALSFRSr) score from baseline to 9 months. Secondary outcome measures were decline in forced vital capacity, fatigue severity (9‐item Fatigue Severity Scale), and quality of life (SF‐36 with physical and mental components analyzed separately). Oxidative stress was assessed in plasma by 8‐hydroxy‐2 deoxyguanosine measurement | |
| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | "Participants were randomized in permuted blocks, stratified by clinical site and riluzole use" Comment: probably done but sequence generation not described |
| Allocation concealment (selection bias) | Unclear risk | Comment: probably done but allocation concealment not described |
| Blinding (performance bias and detection bias) All outcomes | Low risk | "double blind" |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | "Scoring for deceased patients". Imputation for missing data". Comment: these are described in the text |
| Selective reporting (reporting bias) | Low risk | Comment: sufficient information provided |
| Other bias | Low risk | Comment: the study appears to be free of other sources of bias |