Description and comparison of responders and nonresponders
| Responders | Nonresponders | p-value | |
| Sex | |||
| Sex ratio M:F | 0.85 | 1.05 | 0.01 |
| Age | |||
| 25–39 yrs | 4634 (32.9) | 1405 (51.6) | 0.01 |
| 40–59 yrs | 4305 (30.6) | 822 (30.2) | |
| >60 yrs | 5137 (36.5) | 497 (18.2) | |
| Mean age yrs | 51.1 | 43.3 | 0.01 |
| Socioeconomic status | |||
| Manual workers# | 4285 (30.4) | 1061 (38.95) | 0.01 |
| Managers¶ | 3446 (24.5) | 820 (30.1) | 0.01 |
| Nonworking population+ | 6345 (45.1) | 843 (30.95) | 0.01 |
| Habitat | |||
| Rural | 3346 (23.8) | 667 (24.5) | ns |
| Town <100000 inhabitants | 4535 (32.2) | 808 (29.6) | ns |
| Town >100000 inhabitants | 6195 (44.0) | 1249 (45.8) | ns |
| Area | |||
| Paris area | 4993 (35.5) | 1002 (36.8) | ns |
| North & east | 2284 (16.2) | 393 (14.4) | ns |
| West & south-west | 3435 (24.4) | 671 (24.6) | ns |
| South-east & Mediterranean area | 3364 (23.9) | 658 (24.2) | ns |
Data are presented as n (%) unless otherwise stated
M: male
F: female
ns: nonsignificant
#: farmers, employees, workers, etc.
¶: company managers, managerial staff, professional people, middlemen, shopkeepers, foremen, craftsmen etc.
+: retired, others