Table 2

The GRADE quality assessment for CoQ10

Summary of findings
CoQ10 compared to control for migraine prophylaxis
Patient or population: adult patients with migraine
Setting: Healthcare centres
Intervention: CoQ10
Comparison: Placebo
OutcomesAnticipated absolute effects* (95% CI)Relative effect
(95% CI)
No of participants
(studies)
Certainty of the evidence
(GRADE)
Risk with controlRisk with CoQ10
Severity of headache during attack follow-up: 6 weeksThe mean severity of headache during attack was 0MD 1.33 lower
(2.97 lower to 0.31 higher)
371
(6 RCTs)
⨁⨁◯◯
LOW†
Duration of headache attacks follow-up: 6 weeksThe mean duration of headache attacks was 0MD 0.19 lower
(0.27 lower to 0.11 lower)
371
(6 RCTs)
⨁⨁⨁◯
MODERATE‡
Frequency of migraine headache per month follow-up: 6 weeksThe mean frequency of migraine headache per month was 0MD 1.52 lower
(2.4 lower to 0.65 lower)
259
(5 RCTs)
⨁⨁⨁◯
MODERATE‡
  • GRADE Working Group grades of evidence: High certainty indicates we are very confident that the true effect lies close to that of the estimate of the effect.

  • Moderate certainty indicates we are moderately confident in the effect estimate, the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different.

  • Low certainty indicates our confidence in the effect estimate is limited, the true effect may be substantially different from the estimate of the effect.

  • Very low certainty indicates we have very little confidence in the effect estimate, the true effect is likely to be substantially different from the estimate of effect.

  • ⨁⨁⨁ ◯ refers to Quality of the evidence (GRADE)

  • *The risk in the intervention group (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).

  • †There is presence of the statistical heterogeneity, inconsistency and imprecision existed.

  • ‡Downgraded due to large CIs from small sample size and small number of included studies.

  • CoQ10, coenzyme Q10; MD, mean difference; ; RCTs, randomised control trials.