Table 3 Linear mixed effects models of DNA damage measures in roofers (samples from 20 workers at 4 sampling periods, n = 79)
From: Short-term markers of DNA damage among roofers who work with hot asphalt
| Â | Estimate (SE) | p-value |
|---|---|---|
A) Model for γH2axa (lymphocytes) | ||
Fixed effects | ||
 Intercept | 6.97 (0.04) | <0.0001 |
 Smoker (yes/no) | 0.085 (0.04) | 0.04 |
 Period 2 (Monday, after work) | 0.09 (0.03) | 0.008 |
 Period 3 (Thursday, before work) | 0.06 (0.03) | 0.06 |
 Period 4 (Thursday, after work) | 0.1 (0.03) | 0.006 |
 Period 1 (Monday, before work) | 0 (ref.) |  |
Random effects | ||
 Between-subject variance | 0.006 (0.002) | 0.02 |
 Within-subject variance | 0.011 (0.002) | <0.0001 |
 Intraclass correlation coefficient % | 35.3 |  |
B) Model for 8-OHdGa (urine) | ||
Fixed effects | ||
 Intercept | 6.99 (0.19) | <0.0001 |
 Urine creatininea (g/L) | 0.68 (0.08) | <0.0001 |
 Period 2 (Monday, after work) | 0.55 (0.12) | <0.0001 |
 Period 3 (Thursday, before work) | 0.13 (0.12) | 0.27 |
 Period 4 (Thursday, after work) | 0.50 (0.12) | 0.0002 |
 Period 1 (Monday, before work) | 0 (ref.) |  |
Random effects | ||
 Between-subject variance | 0.007 (0.02) | 0.32 |
 Within-subject variance | 0.14 (0.03) | <0.0001 |
 Intraclass correlation coefficient % | 4.8 |  |