Table 1.
Characteristics of the Study Population at the Index Date by Vaccination Status
| Characteristic | Unvaccinated (n = 4 596 074) | Vaccinated (n = 173 745) | Overall (n = 4 769 819) |
|---|---|---|---|
| Age, median (IQR), years | 64 (56–73) | 72 (69–77) | 65 (56–73) |
| Sex | |||
| Male | 2 204 186 (48.0) | 72 397 (41.7) | 2 276 583 (47.7) |
| Female | 2 389 353 (52.0) | 100 849 (58.0) | 2 490 202 (52.2) |
| Unknown | 2535 (0.0) | 499 (0.3) | 3034 (0.0) |
| Race/ethnicity | |||
| Asian | 144 129 (3.1) | 6100 (3.5) | 150 299 (3.1) |
| Black | 513 228 (11.2) | 12 643 (7.3) | 525 871 (11.0) |
| Hispanic | 467 968 (10.2) | 8263 (4.8) | 476 231 (10.0) |
| White | 2 989 949 (65.1) | 128 967 (74.3) | 3 118 916 (65.4) |
| Unknowna | 480 800 (10.5) | 17 772 (10.2) | 498 572 (10.5) |
| Insurance type | |||
| Commercial | 2 443 126 (53.2) | 20 098 (11.6) | 2 463 224 (51.6) |
| Medicare Advantage | 2 152 948 (46.8) | 153 647 (88.4) | 2 306 595 (48.4) |
| Region | |||
| Midwest | 1 121 882 (24.4) | 56 774 (32.7) | 1 178 656 (24.7) |
| Northeast | 602 870 (13.1) | 18 698 (10.8) | 621 568 (13.0) |
| South | 2 155 141 (46.9) | 76 121 (43.8) | 2 231 262 (46.8) |
| West | 644 985 (14.0) | 22 127 (12.7) | 667 112 (14.0) |
| Unknownb | 71 196 (1.5) | 25 (0.0) | 71 221 (1.5) |
| Healthcare utilizationc | |||
| Inpatient stay, % with at least 1 visit | 402 062 (8. 7) | 15 902 (9.2) | 417 964 (8.8) |
| Long-term care, % with at least 1 visit | 94 481 (2.1) | 2426 (1.4) | 96 907 (2.0) |
| Emergency room visit, % with at least 1 visit | 959 170 (20.9) | 34 068 (19.6) | 993 238 (20.8) |
| Outpatient visits, median (IQR) | 1 (0–3) | 2 (1–5) | 1 (0–3) |
| Office visits, median (IQR) | 5 (2–11) | 9 (5–16) | 6 (2–11) |
| Charlson comorbidity index,d median (IQR) | 2 (1–4) | 3 (3–4) | 2 (1–4) |
Values are reported as n (%) unless otherwise indicated. The index date was defined as the date at which an individual was eligible for study inclusion.
Abbreviations: IQR, interquartile range; OLDW, OptumLabs Data Warehouse.
aThe unknown race/ethnicity category includes individuals with either unknown or missing race/ethnicity.
bThe unknown region category includes individuals in either unknown or other regions. In OLDW, the predefined region categories are Midwest, Northeast, South, West, Other, Unknown. The Other and Unknown categories were combined given the low prevalence of herpes zoster in each individual group.
cHealthcare utilization was assessed in the 1 year prior to the index date.
dCharlson comorbidity index was assessed in the 1 year prior to the index date.