Table 3. Incidence of AA by Age, Sex, and Race and Ethnicity.
| Category | Incidence denominator population | AA incidence cohort | Patient-years | Incidence per 100 000 patient-years | Adjusted odds ratio (95% CI) | P value |
|---|---|---|---|---|---|---|
| Overall | 2 896 241 | 2398 | 17 576 550.4 | 13.6 | NA | NA |
| Age, y | ||||||
| 1 | 606 880 | 47 | 398 347.4 | 11.8 | 1 [Reference] | 1 [Reference] |
| 2 | 825 490 | 107 | 683 055.8 | 15.7 | NA | NA |
| 3 | 943 240 | 146 | 814 675.5 | 17.9 | ||
| 4 | 1 017 405 | 187 | 890 844.7 | 21.0 | ||
| 5 | 1 062 273 | 174 | 938 296.9 | 18.5 | ||
| 6 | 1 081 318 | 203 | 956 776.6 | 21.2 | ||
| 7 | 1 084 755 | 191 | 960 416.0 | 19.9 | ||
| 8 | 1 076 042 | 163 | 950 593.8 | 17.1 | ||
| 9 | 1 058 171 | 172 | 930 802.6 | 18.5 | ||
| 10 | 1 033 552 | 139 | 906 584.7 | 15.3 | ||
| 11 | 1 005 499 | 135 | 872 232.3 | 15.5 | ||
| 12 | 969 035 | 140 | 836 169.5 | 16.7 | ||
| 13 | 937 548 | 133 | 809 182.6 | 16.4 | ||
| 14 | 912 306 | 125 | 784 689.5 | 15.9 | ||
| 15 | 891 389 | 117 | 768 184.1 | 15.2 | ||
| 16 | 870 095 | 125 | 752 632.2 | 16.6 | ||
| 17 | 841 275 | 94 | 731 037.9 | 12.9 | ||
| Sex | ||||||
| Male | 1 485 837 | 1110 | 9 045 677.1 | 12.3 | 1 [Reference] | 1 [Reference] |
| Female | 1 410 294 | 1288 | 8 530 401.9 | 15.1 | 0.80 (0.74-0.87) | <.001 |
| Race and ethnicity | ||||||
| Asian | 104 103 | 125 | 542 320.0 | 23.1 | 2.02 (1.67-2.44) | <.001 |
| Black | 563 554 | 644 | 3 788 471.9 | 17.0 | 1.73 (1.55-1.92) | <.001 |
| Hispanic | 319 579 | 581 | 1 845 753.7 | 31.5 | 3.07 (2.76-3.42) | <.001 |
| White | 1 598 707 | 854 | 9 645 530.8 | 8.8 | [Reference] | 1 [Reference] |
| Other/unknowna | 310 298 | 194 | 1 754 474.1 | 11.1 | 1.17 (1.00-1.37) | .047 |
Abbreviation: AA, alopecia areata.
a
Participants self-identified as Other.