Table 1.
Baseline characteristics by exposure group.
| Characteristic | No Herpes zoster | Herpes zoster |
|---|---|---|
| N = 706,901 | N = 177,144 | |
| Years of follow up: | ||
| Mean (SD) | 5.4 (4) | 5.5 (4.1) |
| Median (25th, 75th ptile) | 4.5 (2,8) | 4.7 (2.1,8.3) |
| Age (years): | ||
| Mean (SD) | 65.1 (12.8) | 65.1 (12.9) |
| Median (25th, 75th ptile) | 65 (55.1,74.9) | 65 (55.1,75) |
| Grouped age: | ||
| 40‐ < 50 | 99,866 (14.1) | 24,967 (14.1) |
| 50‐ < 60 | 161,779 (22.9) | 40,444 (22.8) |
| 60‐ < 70 | 184,997 (26.2) | 46,163 (26.1) |
| 70‐ < 80 | 160,827 (22.8) | 40,320 (22.8) |
| 80+ | 99,432 (14.1) | 25,250 (14.3) |
| Male | 282,061 (39.9) | 70,690 (39.9) |
| Annual consultation rate | ||
| Median (25th, 75th ptile) | 6.3 (2.9,11.7) | 8.3 (4.3,14.3) |
| Consultation rate (contacts/yr): | ||
| < 10 | 482,332 (68.2) | 103,060 (58.2) |
| 10‐ < 20 | 159,423 (22.6) | 50,184 (28.3) |
| 20‐ < 30 | 43,054 (6.1) | 15,447 (8.7) |
| 30+ | 22,092 (3.1) | 8453 (4.8) |
| Frailty Index (eFI) | ||
| Median (25th, 75th ptile) | 0.1 (0,0.2) | 0.1 (0.1,0.2) |
| Frailty Index (eFI) group | ||
| Fit | 473,020 (66.9) | 105,095 (59.3) |
| Mild frailty | 160,726 (22.7) | 47,729 (26.9) |
| Moderate frailty | 56,356 (8.0) | 18,445 (10.4) |
| Severe frailty | 16,799 (2.4) | 5875 (3.3) |
| BMI | ||
| Mean (SD) | 27.2 (5.3) | 27.2 (5.3) |
| Median (25th, 75th ptile) | 26.4 (23.5,29.9) | 26.4 (23.6,29.9) |
| BMI category: | ||
| Underweight | 11,594 (1.6) | 2884 (1.6) |
| Normal Weight | 231,470 (32.7) | 59,262 (33.5) |
| Overweight | 243,383 (34.4) | 63,878 (36.1) |
| Obese | 157,956 (22.3) | 41,483 (23.4) |
| Missing | 62,498 (8.8) | 9637 (5.4) |
| Smoking status: | ||
| No | 264,121 (37.4) | 66,004 (37.3) |
| Yes | 155,237 (22.0) | 35,960 (20.3) |
| Ex | 267,329 (37.8) | 74,081 (41.8) |
| Missing | 20,214 (2.9) | 1099 (0.6) |
| Harmful alcohol use | 24,601 (3.5) | 6071 (3.4) |
| Ethnicity | ||
| White | 271,882 (38.5) | 71,625 (40.4) |
| South Asian | 6302 (0.9) | 1376 (0.8) |
| Black | 3485 (0.5) | 559 (0.3) |
| Other | 2530 (0.4) | 615 (0.3) |
| Mixed | 946 (0.1) | 194 (0.1) |
| Unknown | 421,756 (59.7) | 102,775 (58.0) |
| Deprivation group: | ||
| 1 (least deprived) | 138,157 (19.5) | 34,604 (19.5) |
| 2 | 121,460 (17.2) | 30,434 (17.2) |
| 3 | 144,900 (20.5) | 36,320 (20.5) |
| 4 | 142,616 (20.2) | 35,736 (20.2) |
| 5 (most deprived) | 159,768 (22.6) | 40,050 (22.6) |
| Prior history of: | ||
| Asthma | 87,768 (12.4) | 26,956 (15.2) |
| COPD | 63,536 (9.0) | 19,931 (11.3) |
| Diabetes | 75,524 (10.7) | 20,725 (11.7) |
| Uncontrolled diabetes (2 years) | 32,671 (4.6) | 9271 (5.2) |
| Hypertension (diagnosed) | 232,748 (32.9) | 62,436 (35.2) |
| Ischaemic heart disease | 117,646 (16.6) | 34,429 (19.4) |
| Stroke | 25,152 (3.6) | 6595 (3.7) |
| Traumatic brain injury | 5310 (0.8) | 1454 (0.8) |
| Immunosuppressed | 45,957 (6.5) | 19,623 (11.1) |
| Autoimmune disease | 53,030 (7.5) | 18,015 (10.2) |
| Liver disease | 4820 (0.7) | 1359 (0.8) |
| Chronic kidney disease | 51,882 (7.3) | 15,181 (8.6) |
| Depression (2 years) | 14,310 (2.0) | 4316 (2.4) |
| HSV | 23,607 (3.3) | 8535 (4.8) |
| Details of exposure | ||
| Antivirals (in 7 days) | 186 (<1) | 110,997 (62.7) |
| Site of Zoster: | ||
| Ophthalmic | 8775 (5.0) | |
| Non‐truncal (exclud. HZO) | 984 (0.6) | |
| Site unspecified | 167,385 (94.5) | |
| Outcome events: | ||
| Death | 87,371 (12.4) | 25,685 (14.5) |
| Dementia of which (%) of dementia) | 21,213 (3.0) | 5372 (3.0) |
| Alzheimer's | 6571 (31.0) | 1674 (31.2) |
| Vascular | 4876 (23.0) | 1324 (24.7) |
| Other specified | 808 (3.8) | 203 (3.8) |
| Mixed/ unspecified | 8958 (42.2) | 2171 (40.4) |
| Dementia (wider definition)a | 22,902 (3.2) | 5839 (3.3) |
a
Smaller denominator; matched sets discarded if the exposed or all unexposed patients had pre‐study dementia by this definition.