Table 3.
IRRs of infection-related hospital admissions in different time periods after an antibiotic prescription comparing different levels of prior antibiotic use (propensity-matched cohorts with URTI, LRTI, UTI, Otitis Media or Externa)
| CPRD | SAIL | ||||||
|---|---|---|---|---|---|---|---|
| Days 1–3 after | Days 4–30 after | Months 3–6 after | Days 1–3 after | Days 4–30 after | Months 3–6 after | ||
| Quintile of prior antibiotic use | Stratum | IRR (95% CI) | IRR (95% CI) | IRR (95% CI) | IRR (95% CI) | IRR (95% CI) | IRR (95% CI) |
| All | |||||||
| Lowest | Reference | Reference | Reference | Reference | Reference | Reference | |
| Low | 1.01 (0.88–1.16) | 1.20 (1.05–1.37) | 1.23 (1.07–1.42) | 1.10 (0.96–1.25) | 1.07 (0.95–1.19) | 1.33 (1.20–1.48) | |
| Middle | 0.95 (0.84–1.07) | 1.15 (1.03–1.28) | 1.37 (1.21–1.55) | 0.93 (0.79–1.09) | 1.17 (1.03–1.33) | 1.62 (1.43–1.82) | |
| High | 0.90 (0.79–1.02) | 1.32 (1.18–1.49) | 1.77 (1.57–2.00) | 1.06 (0.91–1.25) | 1.42 (1.25–1.61) | 2.10 (1.87–2.36) | |
| Highest | 0.90 (0.77–1.04) | 1.52 (1.34–1.72) | 2.26 (1.92–2.67) | 0.90 (0.74–1.08) | 1.88 (1.63–2.16) | 2.48 (1.17–2.84) | |
| No comorbidity# | |||||||
| Lowest | Reference | Reference | Reference | Reference | Reference | Reference | |
| Low | 1.15 (0.93–1.41) | 1.22 (1.00–1.49) | 1.32 (1.04–1.66) | 1.17 (1.00–1.36) | 1.10 (0.96–1.26) | 1.40 (1.23–1.58) | |
| Middle | 1.01 (0.84–1.22) | 1.10 (0.93–1.31) | 1.66 (1.34–2.07) | 0.98 (0.81–1.19) | 1.23 (1.04–1.45) | 1.75 (1.51–2.03) | |
| High | 0.97 (0.79–1.20) | 1.31 (1.08–1.59) | 2.33 (1.88–2.87) | 1.19 (0.97–1.47) | 1.62 (1.37–1.91) | 2.64 (2.29–3.02) | |
| Highest | 1.18 (0.90–1.55) | 1.44 (1.14–1.81) | 3.22 (2.29–4.53) | 1.01 (0.79–1.30) | 2.46 (2.00–3.02) | 2.90 (2.44–3.45) | |
| Comorbidity# | |||||||
| Lowest | Reference | Reference | Reference | Reference | Reference | Reference | |
| Low | 0.91 (0.75–1.10) | 1.18 (0.99–1.41) | 1.20 (1.00–1.43) | 0.95 (0.74–1.21) | 1.01 (0.84–1.22) | 1.20 (0.99–1.44) | |
| Middle | 0.90 (0.77–1.05) | 1.18 (1.02–1.36) | 1.23 (1.05–1.43) | 0.84 (0.64–1.11) | 1.09 (0.89–1.34) | 1.39 (1.13–1.70) | |
| High | 0.86 (0.73–1.01) | 1.34 (1.16–1.55) | 1.57 (1.33–1.84) | 0.89 (0.69–1.16) | 1.16 (0.95–1.43) | 1.25 (1.01–1.54) | |
| Highest | 0.80 (0.67–0.95) | 1.57 (1.35–1.82) | 2.05 (1.69–2.47) | 0.77 (0.58–1.02) | 1.37 (1.12–1.67) | 2.02 (1.58–2.58) | |
#Based on Charlson Comorbidity Score with score of 0 classified as no comorbidity and scores 1+ as comorbidity present