Table 4. Crude Cumulative Incidence Rates (per 100 Persons) of Incident cSCC by Age Among 440 472 KPNC Members 18 Years or Older, 2009-2019.
| Variable | Crude cumulative incidence rates (95% CI) by age, y | ||||
|---|---|---|---|---|---|
| 18-49 | 50-59 | 60-69 | 70-79 | ≥80 | |
| Patients with AK | |||||
| No. | 26 531 | 53 507 | 73 961 | 42 693 | 23 544 |
| Time since index date, y | |||||
| 0 | 0.4 (0.4-0.5) | 0.9 (0.8-1.0) | 1.5 (1.4-1.6) | 2.4 (2.2-2.5) | 4.1 (3.8-4.3) |
| 1 | 0.9 (0.8-1.0) | 1.9 (1.8-2.0) | 3.1 (2.9-3.2) | 4.7 (4.5-5.0) | 7.7 (7.3-8.0) |
| 2 | 1.4 (1.2-1.5) | 2.9 (2.8-3.1) | 4.6 (4.4-4.8) | 7.1 (6.8-7.3) | 10.7 (10.3-11.1) |
| 3 | 2.1 (1.9-2.3) | 4.0 (3.8-4.2) | 6.2 (6.0-6.4) | 9.6 (9.3-9.9) | 13.6 (13.1-14.1) |
| 4 | 2.8 (2.6-3.1) | 5.3 (5.1-5.5) | 8.0 (7.7-8.2) | 12.1 (11.8-12.5) | 15.9 (15.4-16.5) |
| 5 | 3.4 (3.1-3.7) | 6.6 (6.4-6.9) | 9.9 (9.6-10.2) | 14.7 (14.3-15.1) | 18.0 (17.4-18.6) |
| 6 | 4.3 (4.0-4.7) | 7.9 (7.6-8.2) | 11.7 (11.4-12.1) | 17.0 (16.5-17.5) | 19.7 (19.1-20.3) |
| 7 | 5.2 (4.8-5.7) | 9.2 (8.9-9.6) | 13.7 (13.3-14.0) | 19.3 (18.7-19.8) | 21.3 (20.7-22.0) |
| 8 | 6.4 (5.9-7.0) | 10.6 (10.2-11.1) | 15.9 (15.5-16.3) | 21.6 (21.0-22.2) | 22.5 (21.8-23.2) |
| 9 | 7.4 (6.8-8.1) | 12.0 (11.5-12.5) | 17.6 (17.1-18.1) | 23.6 (22.9-24.3) | 23.4 (22.7-24.1) |
| 10 | 8.2 (7.4-9.0) | 13.4 (12.7-14.2) | 19.3 (18.6-20.0) | 25.9 (24.9-27.0) | 23.9 (23.1-24.7) |
| Matched control patients without AK | |||||
| No. | 26 531 | 53 507 | 73 961 | 42 693 | 23 544 |
| Time since index date, y | |||||
| 0 | 0.0 (0.0-0.1) | 0.4 (0.3-0.5) | 1.3 (1.2-1.4) | 2.4 (2.3-2.6) | 2.9 (2.7-3.1) |
| 1 | 0.1 (0.1-0.2) | 0.7 (0.6-0.8) | 2.1 (2.0-2.2) | 3.8 (3.6-4.0) | 4.5 (4.3-4.8) |
| 2 | 0.2 (0.2-0.3) | 1.0 (0.9-1.0) | 2.8 (2.7-2.9) | 4.8 (4.5-5.0) | 5.6 (5.3-6.0) |
| 3 | 0.3 (0.2-0.4) | 1.2 (1.1-1.3) | 3.4 (3.2-3.5) | 5.6 (5.4-5.9) | 6.4 (6.1-6.8) |
| 4 | 0.4 (0.3-0.5) | 1.5 (1.4-1.7) | 3.9 (3.7-4.1) | 6.3 (6.0-6.6) | 7.0 (6.6-7.3) |
| 5 | 0.4 (0.4-0.6) | 1.9 (1.7-2.0) | 4.5 (4.3-4.7) | 7.1 (6.8-7.4) | 7.5 (7.1-7.9) |
| 6 | 0.6 (0.5-0.7) | 2.2 (2.0-2.3) | 5.0 (4.8-5.2) | 7.7 (7.3-8.0) | 7.8 (7.4-8.2) |
| 7 | 0.6 (0.5-0.8) | 2.4 (2.2-2.6) | 5.5 (5.2-5.7) | 8.3 (7.9-8.7) | 8.1 (7.7-8.5) |
| 8 | 0.9 (0.7-1.2) | 2.7 (2.4-2.9) | 6.0 (5.8-6.3) | 8.7 (8.3-9.1) | 8.4 (8.0-8.8) |
| 9 | 1.0 (0.8-1.3) | 2.9 (2.6-3.2) | 6.6 (6.2-6.9) | 9.0 (8.6-9.4) | 8.6 (8.2-9.1) |
| 10 | 1.2 (0.9-1.5) | 3.2 (2.9-3.6) | 7.0 (6.5-7.5) | 9.6 (8.8-10.4) | 8.7 (8.2-9.2) |
| P valuea | <.001 | <.001 | <.001 | <.001 | <.001 |
Abbreviations: AK, actinic keratosis; cSCC, cutaneous squamous cell carcinoma, Kaiser Permanente Northern California.
a
The Gray test for equality of cumulative incidence functions of cSCC was used for patients with AK and matched control patients.