Table 1. Socio-demographic characteristics of the subjects.
| Parameters | Mean ± SD | n (%) |
| Age (years) | 44.8 ± 9.7 | |
| 25–44 | 147 (50.2) | |
| 45–64 | 139 (47.4) | |
| > 65 | 7 (2.4) | |
| Educational level | ||
| Primary | 77 (26.3) | |
| Secondary | 177 (60.4) | |
| Tertiary | 37 (12.6) | |
| Marital status | ||
| Married | 265 (90.4) | |
| Single | 22 (7.5) | |
| Widowed | 3 (1.0) | |
| Divorced | 3 (1.0) | |
| Number of years as a professional driver | 20.0 ± 10.4 | |
| Number of hours driven per week | 41.9 ± 28.7 | |
| Smoking pattern | ||
| Active smokers | 57 (19.5) | |
| Non-smokers | 217 (74.1) | |
| Ex-smokers | 19 (6.5) | |
| Alcohol use | ||
| User | 208 (71.1) | |
| Teetotaler | 85 (29.0) |