Table 2 Demographic, occupational, health, and work-related psychosocial characteristics of study participants and bivariate associations between these factors and years worked at night shift among men ( n  = 272)
|  | All ( n  = 272) | Years worked at night | p -value | ||
|---|---|---|---|---|---|
<1 ( n  = 33) | 1 to 9 ( n  = 106) | ≥10 ( n  = 133) | |||
Age, mean (SD) | 41.3 (10.2) | 36.2 (10.1) | 35.1 (7.9) | 47.5 (8.0) | <0.001 |
Per capita income (USD)a, mean (SD) | 1,073.7 (743.6) | 909.7 (611.2) | 1,105.1 (762.2) | 1,132.3 (755.4) | 0.283 |
Weekly work hours, mean (SD) | 59.3 (18.7) | 54.2 (20.2) | 58.7 (18.7) | 61.0 (18.3) | 0.166 |
Years of work in nursing, mean (SD) | 14.3 (9.5) | 14.2 (9.7) | 13.7 (9.1) | 14.7 (9.7) | 0.744 |
BMI at 20Â years, mean (SD) | 22.4 (3.0) | 22.7 (2.7) | 22.8 (3.1) | 22.1 (3.1) | 0.217 |
BMI (current), mean (SD) | 27.3 (4.1) | 26.4 (3.4) | 27.0 (3.9) | 27.9 (4.3) | 0.099 |
Marital status (% married) | 69.1 | 54.5 | 62.3 | 78.2 | 0.005 |
Smoking status | Â | Â | Â | Â | Â |
 Never smoker | 72.8 | 78.8 | 74.5 | 69.9 | 0.596 |
 Ex-smoker | 18.8 | 18.2 | 18.9 | 18.8 | |
 Current smoker | 8.4 | 3.0 | 6.6 | 11.3 | |
Alcohol consumption | Â | Â | Â | Â | Â |
 Abstained | 26.8 | 30.3 | 27.4 | 25.6 | 0.145 |
 Low | 18.0 | 12.1 | 14.2 | 22.6 | |
 Medium | 40.1 | 54.5 | 39.5 | 36.8 | |
 High | 15.1 | 3.1 | 18.9 | 15.0 | |
Physical activity (% yes) | 41.2 | 45.5 | 43.4 | 38.3 | 0.636 |
Usual sleep duration, mean (SD) | 6.9 (1.6) | 6.8 (1.5) | 7.0 (1.7) | 6.9 (1.6) | 0.709 |