1. GRADE profile: Triptans versus placebo for acute attacks of vestibular migraine.
| Certainty assessment | № of participants | Effect | Certainty | ||||||||
| № of studies | Study design | Risk of bias | Inconsistency | Indirectness | Imprecision | Other considerations | Triptans | Placebo | Relative (95% CI) | Absolute (95% CI) | |
| Improvement in vertigo (global score): up to 2 hours (assessed with: change from moderate/severe to mild/no vertigo) | |||||||||||
| 2 | Randomised trials | Very seriousa,b | Not serious | Not serious | Seriousc | None | 76/161* (47.2%) | 55/101* (54.5%) | RR 0.84 (0.66 to 1.07) | 87 fewer per 1000 (from 185 fewer to 38 more) | ⨁◯◯◯ Very low |
| Improvement in vertigo (global score): > 12 hours to 72 hours (assessed with: change from moderate/severe to no/mild vertigo) | |||||||||||
| 1 | Randomised trials | Very seriousa,b | Not serious | Not serious | Seriousc | None | 97/109* (89.0%) | 54/61* (88.5%) | RR 1.01 (0.90 to 1.12) | 9 more per 1000 (from 89 fewer to 106 more) | ⨁◯◯◯ Very low |
| Serious adverse events | |||||||||||
| 1 | Randomised trials | Seriousa | Not serious | Not serious | Very seriousc,d | None | 0/75 (0.0%) | 0/39 (0.0%) | Not estimable | ⨁◯◯◯ Very low | |
| Improvement in headache: up to 2 hours (assessed with: change from moderate/severe to mild/no headache) | |||||||||||
| 2 | Randomised trials | Very seriousa,b | Not serious | Not serious | Seriousc | None | 45/154* (29.2%) | 40/94* (42.6%) | RR 0.69 (0.49 to 0.96) | 132 fewer per 1000 (from 217 fewer to 17 fewer) | ⨁◯◯◯ Very low |
| Improvement in headache: > 12 hours to 72 hours (assessed with: change from moderate/severe to mild/no headache) | |||||||||||
| 1 | Randomised trials | Very seriousa,b | Not serious | Not serious | Seriousc | None | 94/109* (86.2%) | 46/62* (74.2%) | RR 1.16 (0.99 to 1.37) | 119 more per 1000 (from 7 fewer to 275 more) | ⨁◯◯◯ Very low |
| Improvement in other migrainous symptoms: nausea and vomiting at up to 2 hours (assessed with: change from moderate/severe to mild/no symptoms) | |||||||||||
| 1 | Randomised trials | Very seriousa,b | Not serious | Not serious | Seriousc | None | 67/150* (44.7%) | 50/89* (56.2%) | RR 0.80 (0.62 to 1.03) | 112 fewer per 1000 (from 213 fewer to 17 more) | ⨁◯◯◯ Very low |
| Improvement in other migrainous symptoms: nausea and vomiting at > 12 to 72 hours (assessed with: change from moderate/severe to mild/no symptoms) | |||||||||||
| 1 | Randomised trials | Very seriousa,b | Not serious | Not serious | Seriousc | None | 101/108* (93.5%) | 57/62* (91.9%) | RR 1.02 (0.93 to 1.11) | 18 more per 1000 (from 64 fewer to 101 more) | ⨁◯◯◯ Very low |
| Improvement in other migrainous symptoms: photo‐ and phonophobia at up to 2 hours | |||||||||||
| 1 | Randomised trials | Very seriousa,b | Not serious | Not serious | Very seriousc,e | None | 59/151* (39.1%) | 33/89* (37.1%) | RR 1.05 (0.75 to 1.47) | 19 more per 1000 (from 93 fewer to 174 more) | ⨁◯◯◯ Very low |
| Improvement in other migrainous symptoms: photo‐ and phonophobia at > 12 to 72 hours | |||||||||||
| 1 | Randomised trials | Very seriousa,b | Not serious | Not serious | Seriousc | None | 95/109* (87.2%) | 45/62* (72.6%) | RR 1.20 (1.01 to 1.42) | 145 more per 1000 (from 7 more to 305 more) | ⨁◯◯◯ Very low |
| Other adverse effects: gastrointestinal disturbance | |||||||||||
| 1 | Randomised trials | Seriousa | Not serious | Not serious | Very seriousc,e | None | 19/75 (25.3%) | 8/39 (20.5%) | RR 1.24 (0.60 to 2.56) | 49 more per 1000 (from 82 fewer to 320 more) | ⨁◯◯◯ Very low |
| Other adverse effects: sleep disturbance | |||||||||||
| 1 | Randomised trials | Seriousa | Not serious | Not serious | Seriousc | None | 51/75 (68.0%) | 11/39 (28.2%) | RR 2.41 (1.43 to 4.07) | 398 more per 1000 (from 121 more to 866 more) | ⨁⨁◯◯ Low |
| Other adverse effects: cardiovascular side effects | |||||||||||
| 1 | Randomised trials | Seriousa | Not serious | Not serious | Very seriousc,e | None | 5/75 (6.7%) | 3/39 (7.7%) | RR 0.87 (0.22 to 3.44) | 10 fewer per 1000 (from 60 fewer to 188 more) | ⨁◯◯◯ Very low |
| Other adverse effects: paraesthesia, flushing, warm or hot sensations | |||||||||||
| 1 | Randomised trials | Seriousa | Not serious | Not serious | Very seriousc,e | None | 7/75 (9.3%) | 5/39 (12.8%) | RR 0.73 (0.25 to 2.14) | 35 fewer per 1000 (from 96 fewer to 146 more) | ⨁◯◯◯ Very low |
| Other adverse effects: headache | |||||||||||
| 1 | Randomised trials | Seriousa | Not serious | Not serious | Very seriousc,e | None | 13/75 (17.3%) | 9/39 (23.1%) | RR 0.75 (0.35 to 1.60) | 58 fewer per 1000 (from 150 fewer to 138 more) | ⨁◯◯◯ Very low |
CI: confidence interval; RR: risk ratio
* Numerator and denominator for this analysis are the number of events with improvement, compared to the total number of events (as opposed to the number of participants).
aSerious risk of attrition bias. Multiple domains rated at unclear risk of bias.
bAnalysis method fails to account for correlation between outcomes reported by the same individual.
cSample size fails to meet the optimal information size, taken to be 300 events for a dichotomous outcome or 400 participants for a continuous outcome, as a rule of thumb.
dNo events in either arm, therefore cannot calculate an effect estimate.
eConfidence interval includes the potential for either substantial benefit or substantial harm from the intervention.