Table 1.
Characteristics of the included participants stratified by sample.
| Calibration sample | Validation sample | p value | |
|---|---|---|---|
| N | 4378 | 4252 | |
| Age [mean (s.d.)] | 50.44 (19.21) | 46.69 (16.17) | <0.001 |
| Male sex [N (%)] | 1805 (41.2) | 1324 (31.2) | <0.001 |
| Country (%) | <0.001 | ||
| Canada | 372 (8.5) | 889 (20.9) | |
| USA | 1675 (38.3) | 518 (12.2) | |
| UK | 126 (2.9) | 135 (3.2) | |
| Germany | 804 (18.4) | 160 (3.8) | |
| Netherlands | 260 (5.9) | 0 (0.0) | |
| Australia | 270 (6.2) | 0 (0.0) | |
| Brazil | 347 (7.9) | 0 (0.0) | |
| Israel | 151 (3.4) | 0 (0.0) | |
| Singapore | 113 (2.6) | 0 (0.0) | |
| Iran | 122 (2.8) | 0 (0.0) | |
| Italy | 138 (3.2) | 0 (0.0) | |
| South Africa | 0 (0.0) | 679 (16.0) | |
| Mexico | 0 (0.0) | 280 (6.6) | |
| Kenya | 0 (0.0) | 192 (4.5) | |
| Zimbabwe | 0 (0.0) | 264 (6.2) | |
| Spain | 0 (0.0) | 1003 (23.6) | |
| Myanmar | 0 (0.0) | 132 (3.1) | |
| Language [N (%)] | <0.001 | ||
| English | 2443 (55.8) | 1542 (36.3) | |
| German | 804 (18.4) | 160 (3.8) | |
| Dutch | 260 (5.9) | 0 (0.0) | |
| Portuguese | 347 (7.9) | 0 (0.0) | |
| Hebrew | 151 (3.4) | 0 (0.0) | |
| Italian | 138 (3.2) | 0 (0.0) | |
| Farsi | 122 (2.8) | 0 (0.0) | |
| South African languages | 0 (0.0) | 679 (16.0) | |
| Spanish | 0 (0.0) | 1283 (30.2) | |
| Malay, Chinese or Tamil | 113 (2.6) | 0 (0.0) | |
| Kiswahili | 0 (0.0) | 192 (4.5) | |
| Shona | 0 (0.0) | 264 (6.2) | |
| Burmese | 0 (0.0) | 132 (3.1) | |
| Method of PHQ-9 administration [N (%)] | <0.001 | ||
| Face to face | 1462 (33.4) | 1693 (39.8) | |
| Internet | 198 (4.5) | 176 (4.1) | |
| Self-administered (mail) | 873 (19.9) | 164 (3.9) | |
| Self-administered (in research setting) | 1845 (42.1) | 2219 (52.2) | |
| Method of SCID administration [N (%)] | <0.001 | ||
| Face to face | 3180 (72.6) | 3477 (81.8) | |
| Computerized (no interviewer) | 147 (3.4) | 0 (0.0) | |
| Phone | 1051 (24.0) | 775 (18.2) | |
| Participant recruitment setting [N (%)] | <0.001 | ||
| Primary Care | 1085 (24.8) | 1399 (32.9) | |
| Outpatient care | 2093 (47.8) | 1591 (37.4) | |
| Inpatient care | 633 (14.5) | 1262 (29.7) | |
| Non-medical setting | 567 (13.0) | 0 (0.0) | |
| SCID major depression = yes [N (%)] | 652 (14.9) | 568 (13.4) | 0.044 |
| PHQ-9 total score [mean (s.d.)] | 6.81 (5.93) | 6.84 (5.96) | 0.801 |
For categorical variables, chi-square tests were performed, for continuous variables independent t tests. M = mean, s.d. = standard deviation, N = sample size.