Demographic and work characteristics of the study population (n=1700)
| Sex ratio (male:female) | 667:1033 |
| Age, median (IQR) | 28 (27–30) |
| Marital status, n (%) | |
| Single | 1036 (61) |
| Married | 655 (38.5) |
| Divorced | 9 (0.5) |
| Number of children, n (%) | |
| 0 | 343 (20.2) |
| 1 | 235 (13.8) |
| >1 | 86 (5.1) |
| Residency level (year), n (%) | |
| I | 320 (18.8) |
| II | 410 (24.1) |
| III | 434 (25.5) |
| IV | 340 (20) |
| V | 196 (11.5) |
| Specialty*, n (%) | |
| Medical | 854 (50.2) |
| Medical and surgical | 221 (13) |
| High-workload medical specialties | 299 (17.6) |
| High-workload surgical specialties | 326 (19.2) |
| Working hours per week, median (IQR) | 60 (48–76) |
| Night shifts per month, median (IQR) | 6 (4–7) |
| Recovery day following night shift, n (%) | 98 (8) |
*Specialties were split into four categories according to everyday difficulties: medical (eg, dermatology, pulmonology, rheumatology, neurology, psychiatry, and fundamental specialties such as histology, physiology and others), medical and surgical (eg, ophthalmology, gynaecology-obstetrics, otorhinolaryngology and others), high-workload medical specialties (eg, critical care medicine, anaesthesiology, emergency medicine, cardiology), and high-workload surgical specialties (surgery, paediatric surgery, orthopaedics, neurosurgery, urology, cardiovascular surgery and others).