Antibiotic use and indications for use by study period
| Month of birth | ||||
| All infants |
January 2010–July 2012
(period 1; pre-CG149) | August 2012–March 2021 (period 2) |
April 2021–December 2022
(period 3; post-NG195) | |
| Number of infants | ||||
| Exposed to ≥1 antibiotic, n (%) | 81 278 (96.0) | 15 726 (95.9) | 55 322 (96.3) | 10 230 (94.6) |
| Any recorded antibiotic indication, n (%) | 29 929 (35.4) | 6228 (38.0) | 20 471 (35.7) | 3230 (29.9) |
| Evidence of bacterial infection, n (%) | 22 273 (26.3) | 4825 (29.4) | 15 125 (26.3) | 2323 (21.5) |
| Record of an antibiotic-resistant organism, n (%) | 1325 (1.6) | 257 (1.6) | 877 (1.5) | 191 (1.8) |
| Necrotising enterocolitis, n (%) | 14 149 (16.7) | 2837 (17.3) | 9723 (16.9) | 1589 (14.7) |
CG149, clinical guideline 149; NG195, NICE guideline 195.