Table 1.
Characteristics of the study population for each common infection
| Characteristic | URTI | LRTI | Sinusitis | Otitis externa | Otitis media | UTI |
|---|---|---|---|---|---|---|
| Unmatched population (n) | 4249147 | 1250120 | 413138 | 702985 | 539571 | 758622 |
| Antibiotics prescribed, n (%) | 1786630 (42) | 1099459 (87.9) | 358647 (86.8) | 230056 (32.7) | 435930 (80.1) | 678236 (89.4) |
| Age, years | ||||||
| mean (SD) | 34.9 (25.2) | 45.5 (26.5) | 44.8 (16.9) | 37.3 (23.6) | 20.7 (21.6) | 48.3 (24.5) |
| 1st–99th centile | 0–88 | 0–93 | 10–83 | 1–87 | 0–80 | 2–94 |
| Matched population (n) | 3291304 | 301272 | 108928 | 459332 | 206806 | 160472 |
| Antibiotic prescribed, n (%) | 1645652 (50) | 150636 (50) | 54464 (50) | 229666 (50) | 103403 (50) | 80236 (50) |
| Age, years | ||||||
| mean (SD) | 37.04 (25.3) | 43.04 (31.6) | 44.72 (17.6) | 34.10 (23.3) | 26.87 (23.7) | 47.69 (28.7) |
| Sex, n (%) | ||||||
| male | 1458758 (44.3) | 143258 (47.6) | 41546 (38.1) | 208908 (45.5) | 95378 (46.1) | 44748 (27.9) |
| female | 1832546 (55.7) | 158014 (52.4) | 67382 (61.9) | 250424 (54.5) | 111428 (53.9) | 115724 (72.1) |
| BMI | ||||||
| mean (SD) | 25.9 (7.15) | 25.23 (7.58) | 26.79 (5.78) | 26.18 (7.33) | 24.56 (8) | 25.6 (6.5) |
| missing, n (%) | 1433930 (43.6) | 140022 (46.5) | 39024 (35.8) | 219029 (47.7) | 112157 (55.2) | 71869 (44.8) |
| Ethnicity, n (%) | ||||||
| White | 908264 (27.6) | 87843 (29.2) | 31043 (28.5) | 121569 (26.5) | 50899 (24.6) | 46411 (28.9) |
| Asian | 80897 ( 2.5) | 4688 (1.6) | 1732 (1.6) | 7336 (1.6) | 3375 (1.6) | 2684 (1.7) |
| Black | 39423 ( 1.2) | 1975 (0.7) | 842 (0.8) | 3182 (0.7) | 1247 (0.6) | 1145 (0.7) |
| Mixed | 21429 ( 0.7) | 1498 (0.5) | 399 (0.4) | 2205 (0.5) | 1147 (0.6) | 728 (0.5) |
| Unknown | 2241291 (68.1) | 205268 (68.1) | 74912 (68.8) | 325040 (70.8) | 150138 (72.6) | 109504 (68.2) |
| Smoking history, n (%) | ||||||
| non-smoker | 1134869 (34.5) | 83866 (27.8) | 47321 (43.4) | 140989 (30.7) | 50365 (24.4) | 62704 (39.0) |
| current smoker | 441827 (13.4) | 43788 (14.5) | 17992 (16.5) | 54057 (11.8) | 17280 (8.4) | 24995 (15.6) |
| past smoker | 519251 (15.8) | 47612 (15.8) | 21172 (19.4) | 75348 (16.4) | 24589 (11.9) | 23824 (14.8) |
| missing smoking information | 1195357 (36.3) | 126006 (41.8) | 22443 (20.6) | 188938 (41.1) | 114572 (55.4) | 48949 (30.5) |
| Region, n (%) | ||||||
| London | 350944 (10.7) | 22099 (7.3) | 10010 (9.2) | 42002 (9.1) | 16474 (8.0) | 14444 (9.0) |
| Scotland, Wales and Northern Ireland | 612872 (18.6) | 56453 (18.7) | 21318 (19.6) | 78311 (17.0) | 33806 (16.3) | 29784 (18.6) |
| North of England | 564625 (17.2) | 60418 (20.1) | 19496 (17.9) | 80982 (17.6) | 39353 (19.0) | 28753 (17.9) |
| Midlands of England | 767371 (23.3) | 76449 (25.4) | 25113 (23.1) | 116423 (25.3) | 53058 (25.7) | 40505 (25.2) |
| South of England | 995492 (30.2) | 85853 (28.5) | 32991 (30.3) | 141614 (30.8) | 64115 (31.0) | 46986 (29.3) |
| IMD quintiles, n (%) | ||||||
| 1 (least deprived) | 497366 (15.1) | 41349 (13.7) | 18367 (16.9) | 74203 (16.2) | 34750 (16.8) | 23261 (14.5) |
| 2 | 478904 (14.6) | 41398 (13.7) | 16743 (15.4) | 68760 (15.0) | 29794 (14.4) | 23526 (14.7) |
| 3 | 412858 (12.5) | 36995 (12.3) | 13152 (12.1) | 58785 (12.8) | 26004 (12.6) | 20485 (12.8) |
| 4 | 387332 (11.8) | 35143 (11.7) | 11109 (10.2) | 52826 (11.5) | 23463 (11.3) | 18522 (11.5) |
| 5 (most deprived) | 310386 ( 9.4) | 32173 (10.7) | 7918 (7.3) | 42033 (9.2) | 19160 (9.3) | 15581 (9.7) |
| missing IMD information | 1204458 (36.6) | 114214 (37.9) | 41639 (38.2) | 162725 (35.4) | 73635 (35.6) | 59097 (36.8) |
| Charlson index score, n (%) | ||||||
| 0 (no comorbidity) | 2354982 (71.6) | 188132 (62.4) | 77024 (70.7) | 346528 (75.4) | 163879 (79.2) | 99283 (61.9) |
| 1–4 (low) | 897586 (27.3) | 105025 (34.9) | 31132 (28.6) | 109419 (23.8) | 41931 (20.3) | 55875 (34.8) |
| ≥5 (high) | 38736 (1.1) | 8115 (2.7) | 772 (0.7) | 3385 (0.73) | 996 (0.5) | 5314 (3.3) |
| Consultation duration, min, median (IQR) | 7 (5–11) | 7 (4–11) | 8 (5–11) | 7 (4–10) | 7 (4–10) | 8 (4–12) |
| Entries to patient EHR, median (IQR)a,b | 13 (5–26) | 17 (7–34) | 14 (6–28) | 10 (4–23) | 9 (4–19) | 19 (7–38) |
| Flu vaccine, n (%)a | 704048 (21.4) | 95968 (31.9) | 21736 (20.0) | 74618 (16.2) | 27295 (13.2) | 50554 (31.5) |
| Same infectious disease, n (%)a | 303939 (9.2) | 22503 (7.5) | 6597 (6.1) | 32381 (7.0) | 12932 (6.3) | 16899 (10.5) |
| Non-antibiotic prescriptions, median (IQR)a | 4 (1–15) | 6 (1–34) | 5 (1–16) | 3 (0–11) | 2 (0–8) | 7 (1–36) |
| Antibiotic prescriptions, n (%)a | ||||||
| none | 2318726 (70.45) | 213291 (70.8) | 73665 (67.63) | 318111 (69.26) | 145050 (70.14) | 112610 (70.2) |
| 1–2 | 824594 (25.05) | 72098 (23.93) | 29875 (27.43) | 120279 (26.19) | 53200 (25.72) | 40454 (25.2) |
| >3 | 147984 (4.5) | 15883 (5.27) | 5388 (4.95) | 20942 (4.56) | 8556 (4.14) | 7408 (4.6) |
Original non-imputed data.
a
In the 12 months preceding the consultation.
b
The number of entries includes all entries in the patient’s EHR on the index date.