Adverse symptomatic outcome (greater than median symptom severity in days 2–4, or greater than median duration of symptoms) according to duration of antibiotic prescribed and antibiotic class
| Poor symptomatic outcome, n (%) | Univariate risk ratio (95% CI, P-value) | Risk ratio controlling for baseline severity, antibiotic type (immediate or delayed), and clustering (95% CI, P-value)a | Risk ratio controlling for propensity score (95% CI, P-value) | Risk ratio controlling for propensity score in imputed dataset (95% CI, P-value) | |
|---|---|---|---|---|---|
| Duration of antibiotic prescription | |||||
| 5 days (reference category) | 105/185 (56.8) | 1.00 | 1.00 | 1.00 | – |
| 7 days | 312/535 (58.3) | 1.03 (0.89 to 1.19) P= 0.713 | 1.03 (0.89 to 1.20) P= 0.685 | 1.06 (0.91 to 1.23) P= 0.443 | 1.06 (0.91 to 1.23) P= 0.462 |
| 10 days | 108/168 (64.3) | 1.13 (0.96 to 1.34) P= 0.148 | 1.13 (0.95 to 1.35) P= 0.162 | 1.22 (1.02 to 1.46) P= 0.026 | 1.22 (1.02 to 1.46) P= 0.026 |
| Antibiotic class | |||||
| Phenoxymethylpenicillin (reference category) | 419/714 (58.7) | 1.00 | 1.00 | 1.00 | 1.00 |
| Other antibiotics | 125/206 (60.7) | 1.03 (0.91 to 1.17) P= 0.603 | 1.04 (0.91 to 1.18) P= 0.547 | 0.98 (0.84 to 1.12) P= 0.807 | 0.94 (0.68 to 1.32) P= 0.733 |
↵a For duration, the model also controls for whether the antibiotics prescribed were immediate or delayed.