Table 1.
Characteristics of the study participants.
| Variables | Case (N = 519) | Control (N = 519) | p Value |
|---|---|---|---|
| Age, years | 64 [57–72] | 64 [59–72] | 0.116 |
| Sex, n (%) | N/A | ||
| Male | 253 (48.75) | 253 (48.75) | |
| Female | 266 (51.25) | 266 (51.25) | |
| Residential radon *, Bq/m3 | 65.46 ± 46.71 | 73.75 ± 60.21 | 0.013 |
| 48.32 [34.43–73.61] | 55.06 [37.71–82.78] | <0.001 | |
| High-radon dwelling †, n (%) | 71 (13.68) | 92 (17.73) | 0.007 |
| Cigarette smoking, n (%) | 222 (42.77) | 181 (34.87) | 0.009 |
| Tobacco consumption, n (%) | <0.001 | ||
| Never-smokers | 297 (57.23) | 338 (65.13) | |
| Light smokers (1–100 pack-years) | 9 (1.73) | 7 (1.35) | |
| Moderate smokers (100–365 pack-years) | 32 (6.17) | 34 (6.55) | |
| Heavy smokers (over 365 pack-years) | 178 (34.30) | 85 (16.38) | |
| Non-response | 3(0.58) | 55(10.60) | |
| Second-hand smoking, n (%) | 239 (46.05) | 110 (21.19) | <0.001 |
| Sleeping hours | 7.20 ± 1.83 | 6.76 ± 1.44 | <0.001 |
| Indoor hours | 15.88 ± 4.39 | 14.17 ± 3.69 | <0.001 |
| Housing type, n (%) | <0.001 | ||
| Single-family house | 178 (34.30) | 373 (71.87) | |
| Apartment | 180 (34.68) | 68 (13.10) | |
| Other multi-family dwelling | 161 (31.02) | 78 (15.03) | |
| Floor of residence | 4.76 ± 5.09 | 2.63 ± 3.69 | <0.001 |
| Presence of house crack, n (%) | 120 (23.12) | 145 (27.94) | 0.075 |
| Construction year | 1996 [1990–2003] | 1997 [1987–2005] | 0.638 |
| Green ratio | 48.09 ± 21.09 | 56.89 ± 18.54 | <0.001 |
* Corrected for seasonal variations. †Residential radon ≥ 100 Bq/m3.