| Variable | CRS | Control group | p-value |
| n = 113 | n = 100 | ||
| Average age (ans) | 41.0 ± 14.7 | 39.1 ± 12.6 | 0.325 |
| Gender (%) |
|
|
|
| Male | 51 (45.1) | 41 (41.0) | 0.543 |
| Female | 62 (54.9) | 59 (59.0) | |
| Occupation (%) |
|
|
|
| Employees | 62 (54.9) | 50 (50.0) | 0.243 |
| Self-employed | 26 (23.0) | 33 (33.0) | |
| Students/Pupils | 25 (22.1) | 17 (17.0) | |
| Level of education (%) |
|
|
|
| Non-university | 49 (43.4) | 38 (38.0) | 0.427 |
| University | 64 (56.6) | 62 (62.0) | |
| Allergy (%) | 24 (21.2) | 16 (16.0) | 0.329 |
| Asthma (%) | 12 (10.6) | 12 (12.0) | 0.750 |
| Controlled diabetes mellitus (%) | 12 (10.6) | 2 (2.0) | 0.011 |
| Controlled hypertension (%) | 20 (17.7) | 6 (6.0) | 0.009 |