Table 1 Demographic characteristics and socio-economic status of the study population
Variables | Case (n = 444) | Control (n = 464) | P-value* |
|---|---|---|---|
Gender (%) | Â | Â | Â |
   Male | 271 (61.0) | 279 (60.1) | 0.78 |
   Female | 173 (39.0) | 185 (39.9) |  |
Age(%), mean ± SD (y) | 41.7 ± 9.6 | 41.3 ± 10.6 |  |
   ≤30 | 49 (11.0) | 61(13.1) | 0.71 |
   31-40 | 163 (36.7) | 158 (34.1) |  |
   41-50 | 162 (36.5) | 163 (35.2) |  |
   51-60 | 51 (11.5) | 60 (12.9) |  |
   61~ | 19 (4.3) | 22 (4.8) |  |
Level of education | Â | Â | Â |
   Illiteracy or primary school | 94 (21.7) | 37 (8.0) | <0.001 |
   High school | 268 (61.8) | 255 (55.1) |  |
   University or above | 72 (16.6) | 171 (36.9) |  |