Table 1.
Estimated posterior probabilities of benefit for a variety of prior assumptions
| Vague prior | Optimistic prior | Sceptical prior | Pessimistic prior | |
|---|---|---|---|---|
| Whole trial (n = 11 558) | ||||
| Any benefit | 64% | 65% | 64% | 62% |
| Small benefit | 43% | 41% | 40% | 38% |
| Modest benefit | 20% | 19% | 19% | 18% |
| Seronegative subgroup (n = 3676) | ||||
| Any benefit | 86% | 87% | 86% | 86% |
| Small benefit | 79% | 78% | 77% | 78% |
| Modest benefit | 68% | 68% | 66% | 67% |
| Seropositive subgroup (n = 5888) | ||||
| Any benefit | 20% | 23% | 21% | 21% |
| Small benefit | 9% | 11% | 11% | 10% |
| Modest benefit | 3% | 4% | 4% | 4% |
| ≤7 days since symptom onset (n = 4466) | ||||
| Any benefit | 95% | 95% | 95% | 95% |
| Small benefit | 90% | 90% | 90% | 90% |
| Modest benefit | 80% | 82% | 82% | 80% |
| >7 days since symptom onset (n = 7086) | ||||
| Any benefit | 17% | 17% | 17% | 17% |
| Small benefit | 7% | 8% | 7% | 7% |
| Modest benefit | 3% | 3% | 2% | 2% |
Vague prior: N(0, SD = 10 000); optimistic prior: N(0.01, SD = 0.007); sceptical prior: N(0, SD = 0.007); pessimistic prior N(−0.01, SD = 0.0036). Small benefit defined as a risk difference >0.5% (equivalent to a NNT ≤200); Moderate benefit defined as a risk difference >1% (equivalent to a NNT ≤100). SD, standard deviation; NNT, number needed to treat.