Demographic characteristics of the study sample
| Baseline characteristics | 2002–2007 N=5485 | 2014–2017 N=9311 | P value |
| Age | 28.9±3.9 | 28.7±3.2 | |
| Female gender n (%) | 3106 (57%) | 4514 (48%) | |
| Unknown | 31 (1%) | 634 (7%) | |
| Specialty n (%)* | |||
| Internal medicine | 1366 (24%) | 2358 (25%) | |
| Family practice | 643 (11%) | 1125 (12%) | |
| Paediatrics | 790 (14%) | 1080 (11%) | |
| General surgery and surgical specialties | 643 (11%) | 934 (10%) | |
| Emergency medicine | 369 (7%) | 687 (7%) | |
| Obstetrics/Gynaecology | 364 (6%) | 509 (5%) | |
| Psychiatry | 251 (4%) | 422 (4%) | |
| Anaesthesiology | 30 (1%) | 430 (4%) | |
| Other (including combined) | 1129 (20%) | 1402 (15%) | |
| Unknown | 95 (2%) | 649 (7%) | |
| University-based programme n (%) | 3643 (66%) | 5661 (61%) | |
| Monthly characteristics | N=30 155 | N=47 946 | |
| Weekly work hours | 71.1±18.4 | 62.1±16.9 | <0.001 |
| Hours engaged in patient care | 49.6±19.6 | 49.3±19.3 | 0.40 |
| Additional weekly work hours related to programme | 3.7±4.2 | 5.0±6.3 | <0.001 |
| Extended duration shifts per month | 4.0±3.4 | 0.2±1.2 | <0.001 |
| Nightly sleep duration | 6.47±1.2 | 6.73±1.1 | <0.001 |
| Sleep duration on extended duration shifts | 2.52±1.5 | 1.87±1.8 | <0.001 |
| Proportion of extended duration shifts without sleep | 0.08±0.27 | 0.29±0.46 | <0.001 |
| Perceived stress | 4.5±1.6 | 4.5±1.6 | 0.99 |
Plus-minus values are means±SD. Unadjusted generalised linear regression models adjusted for clustering of individual responses were used to compare monthly characteristics. Created by the authors.
*Column percentages may not add to 100% due to rounding.