Table 1. Baseline Health and Sociodemographic Characteristics Among Individuals With a Depression Diagnosis and Members of the Comparison Cohorta.
| Characteristic | Depression diagnosis | Comparison cohort | P valueb |
|---|---|---|---|
| Total, No. (%) | 246 499 (100) | 1 190 302 (100) | |
| Sex, No. (%) | |||
| Female | 159 421 (64.7) | 768 876 (64.6) | .46 |
| Male | 87 078 (35.3) | 421 426 (35.4) | |
| Age, No. (%), y | |||
| 18-44 | 109 396 (44.4) | 539 861 (45.4) | <.001 |
| 45-59 | 575 578 (23.4) | 284 927 (23.9) | |
| 60+ | 79 524 (32.3) | 365 514 (30.7) | |
| Year of diagnosis, No. (%) | |||
| 1980-1989 | 12 213 (5.0) | 60 096 (5.0) | .24 |
| 1990-1999 | 42 372 (17.2) | 204 132 (17.1) | |
| 2000-2009 | 97 751 (39.7) | 471 066 (39.6) | |
| 2010-2018 | 94 163 (38.2) | 455 008 (38.2) | |
| Highest education, No. (%)c | |||
| Basic education | 98 952 (40.1) | 383 966 (32.3) | <.001 |
| Youth education | 80 206 (32.5) | 426 828 (35.9) | |
| Higher education | 39 113 (15.9) | 244 562 (20.5) | |
| Missing | 28 228 (11.5) | 134 946 (11.3) | |
| Employment status, No. (%) | |||
| Employed | 99 401 (40.3) | 687 300 (57.7) | <.001 |
| Unemployed | 38 815 (15.7) | 110 497 (9.3) | |
| Early retirement | 41 570 (16.9) | 104 813 (8.8) | |
| State pension | 65 290 (26.5) | 268 592 (22.6) | |
| Missing | 1423 (0.6) | 19 100 (1.6) | |
| Income quartile, No. (%)d | |||
| Below Q1 | 55 435 (22.5) | 239 594 (20.1) | <.001 |
| Q1-Q2 | 77 315 (31.4) | 272 776 (22.9) | |
| Q2-Q3 | 69 952 (28.4) | 313 921 (26.4) | |
| Q3 and above | 43 120 (17.5) | 354 518 (29.8) | |
| Missing | 677 (0.3) | 9493 (0.8) | |
| Marital status, No. (%) | |||
| Married or registered partner | 98 335 (39.9) | 565 060 (47.5) | <.001 |
| Divorced | 33 480 (13.6) | 103 786 (8.7) | |
| Widowed | 28 376 (11.5) | 119 061 (10.0) | |
| Never married | 82 402 (33.4) | 374 725 (31.5) | |
| Missing | 3906 (1.6) | 27 670 (2.3) | |
| Modified CCI, No. (%)e | |||
| Low | 202 221 (82.0) | 1 060 947 (89.1) | <.001 |
| Moderate | 21 224 (8.6) | 56 978 (4.8) | |
| Severe | 15 418 (6.3) | 55 313 (4.6) | |
| Very severe | 7636 (3.1) | 17 064 (1.4) | |
| Baseline health characteristics, No. (%) | |||
| Cardiovascular disease | 48 689 (19.8) | 140 090 (11.8) | <.001 |
| Chronic obstructive pulmonary disease | 11 359 (4.6) | 24 320 (2.0) | |
| Diabetes | 11 403 (4.6) | 29 165 (2.5) | |
| Stroke | 13 855 (5.6) | 29 575 (2.5) | |
| Head injuries | 18 469 (7.5) | 50 976 (4.3) | |
| Anxiety disorders | 15 803 (6.4) | 13 655 (1.1) | |
| Stress disorders | 22 592 (9.2) | 15 896 (1.3) | |
| Bipolar disorder | 10 408 (4.2) | 3619 (0.3) | |
| Substance use disorders | 28 877 (11.7) | 30 523 (2.6) | |
| Personality disorders | 13 578 (5.5) | 9182 (0.8) | |
| Suicide attempt | 5932 (2.4) | 5009 (0.4) |
Abbreviations: CCI, Charlson Comorbidity Index; Q, quartile.
To ensure correct temporal ordering, baseline sociodemographic and health characteristics were measured 2 years before the onset of depression, with baseline characteristics measured beginning January 1, 1978, and depression diagnoses recorded beginning January 1, 1980.
Calculated using χ2 test for categorical variables.
Basic education includes 1 preschool year and 9 school years (grades 1-9); youth education includes high school (grades 10-12); higher education includes university education.
Reflects individual income in the year before the index date.
The CCI is summary measure of hospital-diagnosed comorbidity burden characterized as follows: 0, low; 1, moderate; 2, severe; greater than 2, very severe. The CCI used in all analyses in the present study was modified to exclude diagnoses of dementia, cardiovascular disease, chronic obstructive pulmonary disease, and diabetes.