Table 2.
Subgroup analysis for the outcome ‘cured at day 7’
| Numbers | Antibiotic group, n/N | Control group,a n/N | RD (95% CI) | NNT | RR (95% CI) | P-value for interactionb | |
|---|---|---|---|---|---|---|---|
| All cases | 622 | 246/308 | 223/314 | 0.08 (0.01 to 0.14) | 13 | 1.11 (1.02 to 1.21) | |
| Type of control | 622 | ||||||
| Placebo | 480 | 185/235 | 181/245 | 0.03 (−0.04 to 0.11) | 34 | 1.05 (0.95 to 1.15) | |
| Non-placebo | 142 | 61/73 | 42/69 | 0.23 (0.08 to 0·37) | 5 | 1.40 (1.13 to 1.73) | 0.03 |
| Culture result | 547 | ||||||
| Negative | 255 | 92/127 | 89/128 | 0.02 (−0.09 to 0.12) | 50 | 1.02 (0.88 to 1.19) | |
| Positive | 292 | 119/141 | 113/151 | 0.08 (−0.01 to 0.17) | 13 | 1.11 (0.99 to 1.24) | 0.33 |
| Discharge | 619 | ||||||
| Non-purulent | 266 | 94/126 | 93/140 | 0.08 (−0.03 to 0.19) | 13 | 1.12 (0.96 to 1.31) | |
| Purulent | 353 | 151/181 | 127/172 | 0.09 (0.01 to 0.17) | 12 | 1.12 (1.00 to 1.25) | 0.72 |
| Severity | 599 | ||||||
| Mild redness | 365 | 158/186 | 134/179 | 0.10 (0.02 to 0.18) | 10 | 1.13 (1.02 to 1.25) | |
| Moderate or severe redness | 234 | 77/110 | 77/124 | 0.06 (−0.06 to 0.18) | 17 | 1.10 (0.91 to 1.33) | 0.40 |
| Age, years | 384 | ||||||
| <5 | 287 | 125/145 | 112/142 | 0.07 (−0.01 to 0.16) | 15 | 1.09 (0.98 to 1·22) | |
| 5–18 | 97 | 42/49 | 39/48 | 0.04 (−0.10 to 0.18) | 25 | 1.05 (0.88 to 1.24) | 0.74 |
a
Control group refers to placebo or no antibiotic group according to trial.
b
P-value for interaction calculated using a fixed-effect logistic regression model with trial used as indexing variable. A significant P-value is less than 0.05. NNT = number needed to treat. RD = risk difference. RR = risk ratio.