Summary of findings 1. Avoralstat compared with placebo for preventing hereditary angioedema attacks.
| Avoralstat compared with placebo for preventing HAE attacks | ||||||
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Patient or population: children or adults with Types I or II HAE Settings: outpatient setting Intervention: avoralstat Comparison: placebo | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | No of participants (studies) | Certainty of the evidence (GRADE) | Comments | |
| Risk with placebo |
Risk with avoralstat |
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Risk of HAE attacks (during follow‐up) |
Study population | RR 0.99 (0.92 to 1.06) | 110 (1) | ⊕⊕⊕⊝ Moderatea | — | |
| 1000 per 1000 | 990 per 1000 (920 to 1000) | |||||
|
Change in number of HAE attacks (per week) |
Study population | — | 134 (2) |
⊕⊕⊝⊝ Lowb | — | |
| The mean number of HAE attacks per week ranged across control groups from 0.59 to 1.27 | The mean number of HAE attacks per week in the intervention groups was 0.10 lower (0.37 lower to 0.18 higher) | |||||
|
Mortality (during follow‐up) |
Study population | N/A | N/A | N/A | No deaths reported. | |
| N/A | N/A | |||||
|
Serious adverse events (during follow‐up) |
Study population | RR 0.33 (0.01 to 7.80) | 24 (1) | ⊕⊝⊝⊝ Very lowc | — | |
| 40 per 1000 | 13 per 1000 (0 to 312) | |||||
|
Quality of life
Angioedema Quality of Life scale (lower score is better) (during follow‐up) |
Study population | — | 93 (2) |
⊕⊕⊕⊝ Moderatea | — | |
| The mean change in quality of life ranged across control groups from −0.6 to −12.14 points | The mean change in quality of life in the intervention groups was 6.78 points lower (11.61 lower to 1.95 lower) | |||||
|
Disability (any validated scale) (during follow‐up) |
Study population | N/A | N/A | N/A | Outcome not reported. | |
| N/A | N/A | |||||
|
Adverse events (during follow‐up) |
Study population | RR 0.85 (0.62 to 1.16) | 24 (1) |
⊕⊕⊝⊝ Lowb | — | |
| 830 per 1000 | 706 per 1000 (515 to 963) | |||||
| *The 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). CI: confidence interval; HAE: hereditary angioedema; N/A: not applicable; RR: risk ratio. | ||||||
| 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. | ||||||
aDowngraded one level for imprecision. bDowngraded one level each for imprecision and inconsistency. cDowngraded two levels for imprecision and one level for indirectness.