Table 5.
Oseltamivir versus placebo for prophylaxis of influenza in healthy adults and children
| Outcomes in adults* | Illustrative comparative risks† (95% CI) | Relative effect‡ (95% CI) | No of participants (No of studies) | Risk difference (%) (95% CI) | NNTB or NNTH (95% CI) | |
|---|---|---|---|---|---|---|
| Study population risk | Corresponding intervention risk | |||||
| Symptoms: | ||||||
| Symptomatic influenza in prophylaxis of individuals | 55 per 1000 | 25 per 1000 (17 to 37) | 25 per 1000 (17 to 37) | 2479 (3) | 3.05 (1.83 to 3.88) | NNTB 33 (26 to 55) |
| Asymptomatic influenza in prophylaxis of individuals | 33 per 1000 | 26 per 1000 (16 to 41) | 0.78 (0.49 to 1.24) | 2479 (3) | 0.72 (−0.79 to 1.68) | NNTB 139 (NNTB 60 to ∞ to NNTH 127) |
| Symptomatic influenza in household prophylaxis | 170 per 1000 | 34 per 1000 (15 to 75) | 0.2 (0.09 to 0.44) | 405 (1) | 13.6 (9.52 to 15.47) | NNTB 7 (6 to 11) |
| Asymptomatic influenza in household prophylaxis | 30 per 1000 | 34 per 1000 (12 to 100) | 1.14 (0.39 to 3.33) | 405 (1) | −0.42 (−6.99 to 1.83) | NNTH 239 (NNTH 15 to ∞ to NNT 55) |
| Complications: | ||||||
| Admission to hospital (safety population) | 16 per 1000 | 18 per 1000 (11 to 31) | 1.14 (0.66 to 1.94) | 3434 (4) | −0.22 (−1.51 to 0.55) | NNTH 446 (NNTH 67 to ∞ to NNTB 184) |
| Adverse events: | ||||||
| Headache (on-treatment) | 175 per 1000 | 207 per 1000 (184 to 233) | 1.18 (1.05 to 1.33) | 3434 (4) | −3.15 (−5.78 to −0.88) | NNTH 32 (18 to 115) |
| Nausea (on-treatment) | 43 per 1000 | 85 per 1000 (52 to 138) | 1.96 (1.2 to 3.2) | 3434 (4) | −4.15 (−9.51 to −0.86) | NNTH 25 (11 to 116) |
| Vomiting (on-treatment) | 10 per 1000 | 20 per 1000 (7 to 55) | 1.91 (0.7 to 5.22) | 3434 (4) | −0.95 (−4.41 to 0.31) | NNTH 106 (NNTH 23 to ∞ to NNTB 319) |
| Headache (off-treatment) | 37 per 1000 | 33 per 1000 (23 to 46) | 0.88 (0.63 to 1.24) | 3434 (4) | 0.44 (−0.89 to 1.37) | NNTB 226 (NNTB 74 to ∞ to NNTH 113) |
| Psychiatric body system (on-treatment) | 10 per 1000 | 18 per 1000 (9 to 33) | 1.81 (0.97 to 3.37) | 3434 (4) | −0.79 (−2.31 to 0.03) | NNTH 127 (NNTH 44 to ∞ to NNTB 3415) |
| Psychiatric body system (all events on-treatment and off-treatment) | 13 per 1000 | 23 per 1000 (14 to 40) | 1.80 (1.05 to 3.08) | 3434 (4) | −1.06 (−2.76 to −0.07) | NNTH 94 (36 to 1538) |
| Renal body system (on-treatment) | 3 per 1000 | 10 per 1000 (3 to 32) | 3.17 (0.96 to 10.49) | 2479 (3) | −0.67 (−2.93 to 0.01) | NNTH 150 (NNTH 35 to ∞ to NNTB 8109) |
NNTB=number needed to treat to benefit; NNTH=number needed to treat to harm.
*There are no prophylaxis trials only in children.
†To estimate treatment effects we first calculated risk ratios and used the average (mean) control event rate and pooled risk ratios reported in figures to calculate risk differences.
‡Values are risk ratios unless stated otherwise.