Sociodemographic characteristic | Group A | Group B | Total | χ2value | P value | |||
---|---|---|---|---|---|---|---|---|
 | Number | Percentage (%) | Number | Percentage (%) |  | |||
Education level | Primary school and lower | 372 | 98.41 | 6 | 1.59 | 378 | Â | Â |
 | Junior and senior high school | 626 | 98.12 | 12 | 1.88 | 638 | 14.835 | 0.001 |
 | Junior college and higher | 270 | 94.08 | 17 | 5.92 | 287 |  |  |
Total | 1,268 | Â | 35 | Â | 1,303* | Â | Â | |
Occupation | Manual work | 984 | 96.09 | 40 | 3.91 | 1,024 | Â | Â |
 | Intellectual work | 569 | 91.63 | 52 | 8.37 | 621 | 15.902 | <0.001 |
 | Other** | 344 | 95.56 | 16 | 4.44 | 360 |  |  |
Total | 1,897 | Â | 108 | Â | 2,005* | Â | Â | |
Age (years) | <35 | 114 | 82.01 | 25 | 17.99 | 139 | 59.602 | <0.001 |
 | 35–49 | 1,074 | 93.80 | 71 | 6.20 | 1,145 |  |  |
 | 50–64 | 774 | 97.60 | 19 | 2.40 | 793 |  |  |
 | >64 | 198 | 96.12 | 8 | 3.88 | 206 |  |  |
Total | 2,160 | Â | 123 | Â | 2,283 | Â | Â |