Table 4.
Effect of antibiotic prescribing strategy on all clinical outcomes in one stage random effects IPD meta-analysis. Values are means (95% confidence intervals) unless stated otherwise
| Outcome | Delayed v no antibiotics | Delayed v immediate antibiotics | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| No of participants (none) | No of participants (delayed) | No antibiotics | Delayed | Adjusted* estimate (95% CI) | No of participants (immediate) | No of participants (delayed) | Immediate | Delayed | Adjusted* estimate (95% CI) | ||
| Follow-up symptom severity score on days 2-4 | |||||||||||
| RCT+OS | 2716 | 1192 | 2.499 (1.44 to 3.56) | 2.496 (1.47 to 3.52) | −0.003 (−0.12 to 0.11) | 2699 | 1053 | 2.68 (1.26 to 4.11) | 2.70 (1.36 to 4.05) | 0.02 (−0.11 to 0.15) | |
| RCT | 484 | 815 | 2.77 (1.13 to 4.11) | 2.86 (1.6 to 4.06) | 0.09 (−0.10 to 0.28) | 606 | 674 | 2.29 (0.66 to 3.93) | 2.40 (0.78 to 4.03) | 0.11 (−0.004 to 0.22) | |
| OS | 2232 | 377 | 2.22 (1.86 to 2.59) | 2.12 (1.74 to 2.50) | −0.10 (−0.12 to −0.08)† | 2093 | 379 | 2.75 (2.24 to 3.26) | 2.63 (2.05 to 3.20) | −0.12 (−0.33 to 0.07) | |
| Time to complete symptom resolution (days) | |||||||||||
| RCT+OS | 3091 | 1123 | 11.5 (6.4 to 16.6) | 11.6 (6.4 to 16.6) | 1.00 (0.82 to 1.23)‡ | 3275 | 1442 | 10.9 (6.3 to 15.6) | 11.4 (6.8 to 15.9) | 1.04 (1.01 to 1.08)†‡ | |
| RCT | 540 | 647 | 9.42 (4.22 to 14.62) | 9.88 (4.37 to 15.38) | 1.04 (0.95 to 1.13) | 876 | 962 | 9.94 (7.17 to 12.70) | 11.37 (8.19 to 14.54) | 1.14 (1.06 to 1.22)† | |
| OS | 2551 | 476 | 15.1 (14.8 to 15.4) | 15.5 (15.2 to 15.8) | 0.98 (0.94 to 1.01) | 2399 | 480 | 11.96 (5.90 to 18.03) | 12.37 (6.40 to 18.35) | 1.02 (0.97 to 1.07)‡ | |
| Duration of moderately severe or severe symptoms (days) | |||||||||||
| RCT+OS | 2997 | 1251 | 6.2 (5.0 to 7.5) | 6.3 (5.0 to 7.5) | 1.01 (0.91 to 1.12) | 2744 | 902 | 5.8 (4.5 to 7.2) | 6.4 (5.3 to 7.6) | 1.08 (1.01 to 1.17)† | |
| RCT | 447 | 775 | 6.88 (4.21 to 9.56) | 6.81 (4.16 to 9.46) | 1.04 (0.94 to 1.15) | 347 | 426 | 6.36 (5.85 to 6.86) | 7.48 (6.94 to 8.02) | 1.18 (1.06 to 1.31)†‡ | |
| OS | 2550 | 476 | 6.59 (5.45 to 6.74) | 6.74 (6.60 to 6.87) | 0.97 (0.93 to 1.01) | 2397 | 476 | 5.36 (4.02 to 6.70) | 5.94 (4.86 to 7.02) | 1.05 (0.96 to 1.16)‡ | |
| Reconsultation (%, 95% CI) | |||||||||||
| RCT+OS | 16 232 | 5901 | 17 (4 to 58) | 13 (2 to 52) | 0.72 (0.60 to 0.87)† | 22 430 | 6157 | 22 (4 to 58) | 16 (3 to 59) | 0.95 (0.74 to 1.22) | |
| RCT | 509 | 611 | 25 (15 to 22) | 21 (10 to 31) | 0.92 (0.67 to 1.26) | 796 | 865 | 25 (5 to 41) | 24 (8 to 41) | 1.29 (0.84 to 1.99) | |
| OS | 15 723 | 5290 | 16 (4 to 60) | 12 (2 to 54) | 0.54 (0.49 to 0.60)† | 21 634 | 5292 | 22 (4 to 58) | 15 (3 to 59) | 0.70 (0.66 to 0.75)† | |
| Complication (hospital admission or death; %, 95% CI) | |||||||||||
| RCT+OS | 16 364 | 5827 | 0.6 (0.03 to 14) | 0.4 (0.02 to 11) | 0.62 (0.30 to 1.27) | 22 371 | 6017 | 0.8 (0.1 to 5) | 0.6 (0.1 to 4) | 0.78 (0.53 to 1.13) | |
| RCT | 431 | 530 | 0.6 (0.02 to 14) | 2.09 (0.01 to 22) | 0.35 (0.07 to 1.92) | 650 | 719 | 0.9 (0.3 to 5) | 1.0 (0.3 to 4) | 1.25 (0.38 to 4.16) | |
| OS | 15 933 | 5297 | 0.6 (0.01 to 3.7) | 0.4 (0.01 to 2.2) | 0.64 (0.28 to 1.43) | 21 721 | 5298 | 0.7 (0.3 to 1.7) | 0.6 (0.2 to 1.6) | 0.22 (0.19 to 0.27)† | |
| Patient satisfaction score | |||||||||||
| RCT+OS | 1434 | 674 | 2.96 (2.55 to 3.36) | 3.04 (2.64 to 3.44) | 0.09 (0.06 to 0.11)† | 1743 | 805 | 2.99 (2.33 to 3.64) | 2.87 (2.25 to 3.49) | −0.12 (−0.26 to 0.03) | |
| RCT | 433 | 520 | 3.17 (2.82 to 3.51) | 3.26 (2.92 to 3.60) | 0.06 (−0.03 to 0.16) | 563 | 649 | 3.20 (2.33 to 4.06) | 3.07 (2.22 to 3.92) | −0.13 (−0.31 to 0.05) | |
| OS | 1001 | 154 | 2.77 (2.15 to 3.39) | 2.85 (2.25 to 3.46) | 0.10 (−0.03 to 0.23) | 1180 | 156 | 2.88 (2.07 to 3.69) | 2.77 (2.01 to 3.52) | −0.06 (−0.18 to 0.06) | |
Adjusted estimate=coefficient, odds ratio, or relative risk; IPD=individual patient data; OS=observational study; RCT=randomised controlled trial.
*
Adjusted for baseline severity, age, and condition.
†
Statistically significant result. The number of observations for each outcome varies as not all studies collected data on all outcomes; analyses used all available data for each outcome.
‡
Estimated using fixed study specific effects and random treatment effect due to convergence difficulties.