Table 1.
Demographic Characteristics of Selected Cohort
| Characteristics | Full Cohort N=18,307 | Chronic Use N=1819 | Non-Chronic Use N=16,488 | P value |
|---|---|---|---|---|
| Gender | 0.65 | |||
| Male | 6065 (33.13%) | 594 (32.66%) | 5471 (33.26%) | |
| Female | 12,242 (66.87%) | 1225 (67.34%) | 11,017 (66.98%) | |
| Age [mean (SD)] | 58.46 (18.24) | 60.40 (17.52) | 58.24 (18.30) | <0.001 |
| Age class | <0.001 | |||
| 0–17 | 93 (0.51%) | 10 (0.55%) | 83 (0.50%) | |
| 18–39 | 2979 (16.27%) | 230 (12.64%) | 2749 (16.71%) | |
| 40–59 | 6432 (35.13%) | 597 (32.82%) | 5835 (35.48%) | |
| 60–79 | 6096 (33.30%) | 704 (38.70%) | 5392 (32.78%) | |
| 80+ | 2707 (14.79%) | 278 (15.28%) | 2429 (14.77%) | |
| Living area | <0.001 | |||
| Urban | 8159 (44.57%) | 820 (45.08%) | 7339 (44.62%) | |
| Rural | 6669 (36.43%) | 729 (40.08%) | 5940 (36.11%) | |
| Missing | 3479 (19.00%) | 270 (14.84%) | 13,279 (19.46%) | |
| First prescriber | 0.85 | |||
| GP | 15,226 (83.17%) | 1533 (84.28%) | 13,693 (83.05%) | |
| Specialist | 2743 (14.98%) | 280 (15.39%) | 2463 (14.94%) | |
| Missing | 338 (1.85%) | 6 (0.33%) | 332 (02.01%) | |
| Initial antidepressant drug | <0.001 | |||
| Sertraline | 4798 (26.21%) | 671 (36.89%) | 4127 (25.09%) | |
| Paroxetine | 2951 (16.21%) | 273 (15.01%) | 2678 (16.28%) | |
| Citalopram | 2535 (13.85%) | 244 (13.41%) | 2291 (13.93%) | |
| Trazodone | 2061 (11.26%) | 60 (3.30%) | 2001 (12.17%) | |
| Escitalopram | 1512 (8.26%) | 186 (10.23%) | 1326 (8.06%) | |
| Amitriptyline | 1390 (7.59%) | 25 (1.37%) | 1365 (8.30%) | |
| Venlafaxine | 894 (4.88%) | 105 (5.77%) | 789 (4.80%) | |
| Duloxetine | 675 (3.69%) | 79 (4.39%) | 596 (3.62%) | |
| Fluoxetine | 496 (2.71%) | 46 (2.53%) | 450 (2.74%) | |
| Mirtazapine | 336 (1.84%) | 38 (2.09%) | 298 (1.81%) | |
| Other | 317 (1.73%) | 18 (0.99%) | 299 (1.82%) | |
| Polytherapy | 342 (1.87%) | 74 (4.07%) | 268 (1.63%) | |
| Polypharmacy | <0.001 | |||
| Yes | 5411 (29.56%) | 394 (21.66%) | 5017 (30.50%) | |
| No | 12,896 (70.44%) | 1425 (78.34%) | 11,471 (69.74%) |
Notes: Chronic use: at least 180 Defined Daily Dose (DDD) of antidepressant drug claimed in every year of follow-up. P values: all p-values but for age [mean (SD)], which was performed with independent Student t tests, were obtained by using chi square tests. Specialist: hospital or mental health center physician. Polytherapy: a combination of more than one antidepressant drugs as the initial treatment. Polypharmacy: 5 or more drugs claimed concomitantly.
Abbreviations: SD, standard deviation; GP, general practitioner.