Table 2. Dementia Risk Among Individuals With a Depression Diagnosis and Members of the Comparison Cohorta .
| Age | Depression diagnosis | Comparison cohort | Risk difference (95% CI)b | P value | ||
|---|---|---|---|---|---|---|
| Events/No. at risk | Dementia risk (95% CI)a | Events/number at risk | Dementia risk (95% CI)a | |||
| Overall | ||||||
| 1-10 y | 10 774/246 499 | 5.33 (5.23 to 5.43) | 23 420/1 190 302 | 2.57 (2.53 to 2.60) | 2.76 (2.56 to 2.97) | <.001 |
| >10-20 y | 2637/95 296 | 4.55 (4.37 to 4.74) | 11 697/534 344 | 3.56 (3.49 to 3.62) | 1.00 (0.62 to 1.37) | |
| >20-39 y | 589/19 206 | 9.82 (8.74 to 11.0) | 3535/123 570 | 9.09 (8.68 to 9.52) | 0.73 (−1.55 to 3.01) | |
| 1-39 y | 14 000/246 499 | 13.6 (13.0 to 14.2) | 38 652/1 190 302 | 11.51 (11.2 to 11.8) | 2.09 (0.81 to 3.37) | |
| Women | ||||||
| 1-10 y | 7297/159 421 | 5.57 (5.45 to 5.70) | 17 092/768 876 | 2.89 (2.85 to 2.93) | 2.68 (2.42 to 2.95) | <.001 |
| >10-20 y | 1879/63 351 | 4.89 (4.66 to 5.12) | 8660/348 215 | 4.00 (3.91 to 4.09) | 0.89 (0.41 to 1.37) | |
| >20-39 y | 450/13 286 | 10.3 (9.12 to 11.5) | 2665/83 321 | 9.73 (9.26 to 10.2) | 0.53 (−1.91 to 2.97) | .68 |
| 1-39 y | 9626/159 421 | 14.5 (13.8 to 15.1) | 28 417/768 876 | 12.6 (12.3 to 12.9) | 1.88 (0.47 to 3.29) | <.001 |
| Men | ||||||
| 1-10 y | 3477/87 078 | 4.86 (4.70 to 5.02) | 6328/421 426 | 1.97 (1.92 to 2.01) | 2.89 (2.57 to 3.22) | <.001 |
| >10-20 y | 758/31 945 | 3.87 (3.58 to 4.17) | 3037/186 129 | 2.70 (2.60 to 2.81) | 1.16 (0.57 to 1.75) | |
| >20-39 y | 139/5920 | 8.85 (6.30 to 11.9) | 870/40 249 | 7.67 (6.79 to 8.62) | 1.18 (−4.16 to 6.52) | .68 |
| 1-39 y | 4374/87 078 | 11.9 (10.6 to 13.4) | 10 235/421 426 | 9.35 (8.74 to 9.98) | 2.59 (−0.37 to 5.55) | .09 |
| 18-44 y | ||||||
| 1-10 y | 191/109 396 | 0.24 (0.20 to 0.27) | 140/539 861 | 0.04 (0.03 to 0.05) | 0.20 (0.13 to 0.26) | <.001 |
| >10-20 y | 141/51 680 | 0.51 (0.43 to 0.61) | 199/258 077 | 0.15 (0.13 to 0.18) | 0.36 (0.19 to 0.54) | |
| >20-39 y | 109/11 117 | 4.67 (3.71 to 5.79) | 310/61 304 | 2.75 (2.38 to 3.17) | 1.92 (−0.13 to 3.97) | .67 |
| 1-39 y | 441/109 396 | 4.83 (3.97 to 5.80) | 649/539 861 | 2.84 (2.48 to 3.24) | 1.99 (0.14 to 3.84) | .04 |
| 45-59 y | ||||||
| 1-10 y | 915/57 578 | 2.00 (1.87 to 2.13) | 796/284 927 | 0.38 (0.35 to 0.40) | 1.62 (1.37 to 1.88) | <.001 |
| >10-20 y | 678/26 671 | 4.26 (3.94 to 4.60) | 1456/150 333 | 1.67 (1.58 to 1.76) | 2.59 (1.94 to 3.25) | |
| >20-39 y | 310/6378 | 16.8 (14.2 to 19.7) | 1623/43 535 | 15.3 (14.3 to 16.3) | 1.57 (−3.99 to 7.12) | .59 |
| 1-39 y | 1903/57 578 | 15.5 (13.9 to 17.2) | 3875/284 927 | 14.3 (13.4 to 15.1) | 1.27 (−2.30 to 4.84) | .50 |
| ≥60 y | ||||||
| 1-10 y | 9668/79 525 | 14.0 (13.7 to 14.2) | 22 484/365 514 | 7.54 (7.45 to 7.64) | 6.43 (5.89 to 6.98) | <.001 |
| >10-20 y | 1818/16 945 | 14.6 (14.0 to 15.3) | 10 042/125 934 | 11.4 (11.2 to 11.6) | 3.21 (1.89 to 4.53) | |
| >20-39 y | 170/1711 | 16.4 (14.0 to 18.9) | 1602/18 731 | 15.5 (14.7 to 16.3) | 0.87 (−4.09 to 5.83) | .74 |
| 1-39 y | 11 656/79 525 | 20.1 (19.8 to 20.5) | 34 128/365 514 | 17.3 (17.1 to 17.5) | 2.86 (1.99 to 3.72) | <.001 |
a
For the study population overall and within strata defined by sex and age at depression diagnoses, we present results further stratified by the time elapsed between the index date and the depression diagnoses (1-10 years; >10-20 years; >20-30 years; 1-39 years).
b
Dementia risk per 100 individuals was calculated using the cumulative incidence function, accounting for the competing risk of death. Risk differences were calculated as the difference in dementia risk among individuals with a depression diagnosis and the comparison cohort. The null value for a risk difference is zero.