Table 1.
Demographic and clinical characteristics of study population included in cohort study by exposure status at cohort entry into study period, for all CPRD patients and for subset of patients with HES-ONS linked data. Values are numbers (percentages)
| Characteristic | Complete cohorts (n=320 000) | HES-ONS linked patients (n=257 886) | |||
|---|---|---|---|---|---|
| Unexposed (n=160 000) | Exposed (n=160 000) | Unexposed (n=128 943) | Exposed (n=128 943) | ||
| Smoking: | |||||
| Never smoked | 59 581 (37.2) | 57 805 (36.1) | 47 243 (36.7) | 45 757 (35.5) | |
| Smoker | 53 889 (33.7) | 68 612 (42.9) | 43 633 (33.8) | 55 935 (43.4) | |
| Missing | 46 530 (29.1) | 33 583 (21.0) | 38 067 (29.5) | 27 251 (21.1) | |
| Alcohol use: | |||||
| Never drinker | 48 961 (30.6) | 51 747 (32.3) | 40 394 (31.3) | 42 716 (33.1) | |
| Ever drinker | 38 292 (23.9) | 46 524 (29.1) | 29 364 (22.8) | 36 246 (28.1) | |
| Missing | 72 747 (45.5) | 61 729 (38.6) | 59 185 (45.9) | 49 981 (38.8) | |
| Index of Multiple Deprivation fifths*: | |||||
| Unavailable | 4833 (3.0) | 4333 (2.7) | 24 (0.02) | 26 (0.02) | |
| 1 (least deprived) | 41 096 (25.7) | 36 149 (22.6) | 34 359 (26.6) | 29 987 (23.3) | |
| 2 | 37 827 (23.6) | 36 504 (22.8) | 31 588 (24.5) | 30 236 (23.4) | |
| 3 | 30 651 (19.2) | 30 904 (19.3) | 25 464 (19.8) | 25 739 (20.0) | |
| 4 | 27 332 (17.1) | 30 002 (18.8) | 22 542 (17.5) | 24 867 (19.3) | |
| 5 (most deprived) | 18 261 (11.4) | 22 108 (13.8) | 14 966 (11.6) | 18 088 (14.0) | |
| Charlson comorbidity index score: | |||||
| 0 | 99 492 (62.2) | 72 290 (45.2) | 79 978 (62.0) | 58 048 (45.0) | |
| 1-2 | 48 287 (30.2) | 63 461 (39.7) | 39 124 (30.4) | 51 098 (39.6) | |
| 3-4 | 9510 (5.9) | 17 494 (10.9) | 7775 (6.0) | 14 413 (11.2) | |
| >5 | 2711 (1.7) | 6755 (4.2) | 2066 (1.6) | 5384 (4.2) | |
| No of general practitioner visits: | |||||
| ≤5 | 87 286 (54.5) | 37 605 (23.5) | 69 788 (54.1) | 29 582 (22.9) | |
| >5 | 72 714 (45.4) | 122 395 (76.5) | 59 155 (45.9) | 99 361 (77.1) | |
| Immunosuppression† | 4882 (3.0) | 16 609 (10.3) | 3866 (3.0) | 13 723 (10.6) | |
| Non-topical corticosteroid use | 5832 (3.6) | 15 990 (9.9) | 4814 (3.7) | 13 221 (10.2) | |
| Opioid prescriptions | 1557 (0.9) | 9469 (5.9) | 1261 (0.9) | 7809 (6.0) | |
CPRD=Clinical Practice Research Datalink; HES=Hospital Episode Statistics; ONS=Office for National Statistics.
*Socioeconomic status is based on Index of Multiple Deprivation; values are percentage of people who had deprivation status available.
†Immunosuppressed patients defined according to criteria to contraindicate vaccination.27