Table 2.
Amitriptyline compared to placebo for migraine prophylaxis
| Patient or population: migraine Intervention: prophylaxis with amitriptyline Comparison: placebo | |||||
|---|---|---|---|---|---|
| Outcomes | № of participants (studies) | Certainty of the evidence (GRADE) | Relative effect (95% CI) | Anticipated absolute effectsa | |
| Risk with placebo | Risk difference with Amitriptyline | ||||
| 50% or more reduction in monthly migraine days | 389 (3 RCTs) |
Moderate (downgraded due to risk of bias) |
RR 1.60 (1.17 to 2.19) | 275 per 1,000 | 165 more per 1,000 (47 more to 327 more) |
| Monthly migraine days | 118 (1 RCT) | High | - | NA | MD 1.2 migraine days fewer (2.1 fewer to 0.3 fewer) |
| Adverse events leading to discontinuation | 507 (2 RCTs) |
Moderate (downgraded due to risk of bias) |
RD 0.05 (0.01 to 0.10) | 0 per 1,000 | 50 more per 1,000 (10 more to 100 more) |
CI confidence interval, MD mean difference, RR risk ratio, RD Risk difference
GRADE Working Group grades of evidence
High certainty: we are very confident that the true effect lies close to that of the estimate of the effect
Moderate certainty: 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: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect
Very low certainty: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect
aThe risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI)