Table 2.
Trend of HZ incidence rates per 1000 persons among patients with IC/AID in the Republic of Korea from 2016 to 2020, stratified by year, age, sex, IC/AIDs, and HZ-related complications
| Number of patients with IC/AID, n | Number of HZ cases; na, b | Annual incidence rates; n (95% CIc)d,e | |
|---|---|---|---|
| Year | |||
| 2016 | 557,521 | 11,838 | 21.23 (20.86–21.62) |
| 2017 | 765,793 | 18,486 | 24.14 (23.80–24.49) |
| 2018 | 941,930 | 23,100 | 24.52 (24.21–24.84) |
| 2019 | 1,101,371 | 26,759 | 24.30 (24.01–24.59) |
| 2020 | 1,229,948 | 28,129 | 22.87 (22.61–22.87) |
| Average | 919,313 | 21,662 | 23.41 (22.21–24.62) |
| Age group, yearsf | |||
| 18–29 | 68,397 | 720 | 10.43 (9.88–10.97) |
| 30–39 | 100,474 | 1654 | 16.29 (15.35–17.23) |
| 40–49 | 148,169 | 2787 | 18.56 (17.24–19.88) |
| 50–59 | 217,792 | 5715 | 26.11 (24.83–27.39) |
| 60–64 | 106,611 | 3203 | 29.85 (28.37–31.34) |
| 65–69 | 84,722 | 2587 | 30.43 (29.17–31.69) |
| 70–79 | 132,640 | 3721 | 28.08 (26.27–29.89) |
| 80+ | 60,506 | 1276 | 21.67 (19.93–23.42) |
| Sexf | |||
| Male | 400,841 | 7633 | 18.96 (18.03–19.89) |
| Female | 518,472 | 14,030 | 26.85 (25.40–28.31) |
| IC/AIDf | |||
| Aplastic anemia | 11,749 | 308 | 26.67 (24.50–28.83) |
| Decompensated liver cirrhosis | 35,079 | 533 | 15.19 (13.74–16.64) |
| Hemato-oncology conditions | 59,356 | 2051 | 35.47 (31.62–39.32) |
| Human immunodeficiency virus infection | 12,366 | 258 | 20.92 (19.57–22.26) |
| Myelodysplastic syndrome | 8,570 | 219 | 26.16 (23.50–28.81) |
| Ankylosing spondylitis | 62,157 | 1188 | 18.74 (17.01–20.48) |
| Crohn’s disease | 14,254 | 278 | 19.36 (17.17–21.56) |
| Psoriasis | 274,803 | 5172 | 18.46 (16.80–20.12) |
| Rheumatoid arthritis | 431,343 | 11,562 | 26.55 (24.87–28.24) |
| Systemic lupus erythematosus | 34,834 | 1072 | 30.84 (29.72–31.96) |
| Transplants (including solid organ and hematopoietic stem cell transplants) | 26,501 | 979 | 37.12 (35.45–38.79) |
| Ulcerative colitis | 50,526 | 1101 | 21.46 (19.62–23.30) |
| HZ complicationsf | |||
| Cutaneous | 1202 | 1.29 (1.21–1.38) | |
| Disseminated | 329 | 0.36 (0.34–0.39) | |
| Ocular | 812 | 0.88 (0.83–0.93) | |
| Neurologic | 270 | 0.29 (0.27–0.31) | |
| Postherpetic neuralgia | 1793 | 1.87 (1.42–2.31) | |
| Other complications | 4493 | 3.84 (1.95–5.73) | |
| All complications | 6980 | 7.58 (7.22–7.93) | |
| No complications | 14,683 | 15.84 (14.95–16.72) | |
AID autoimmune disease, CI confidence interval, HZ herpes zoster, IC immunocompromised condition
aHZ defined as HZ diagnostic codes plus antiviral medications (acyclovir, valacyclovir, or famciclovir) dispensed within ± 7 days of the HZ diagnosis date in the main analysis
bThe average number of HZ cases was calculated as the total number of HZ cases in each subgroup divided by the duration of the study period (5 years)
c95% confidence intervals were calculated by using exact binomial method
dDenominator represents the sum of the number of patients with IC/AID
ePer 1000 persons
fValues in these sections are averaged across the 5-year period of the study