Table 7

Model summaries for regression models relating PCE in exhaled breath to PCE TWA

Model
Intercept
Day
Body mass index
ln (PCE TWA)
≈ R2

Same day post-shift (34 observations on 18 workers)
-0.46 ± 0.53 (0.40)a
-b
0.042 ± 0.018 (0.036)
0.52 ± 0.082 (<0.0001)
61%
Next day pre-shift (35 observations on 18 workers)
-0.42 ± 0.35 (0.25)
0.15 ± 0.051 (0.011)
0.028 ± 0.012 (0.038)
0.15 ± 0.045 (0.0032)
47%
Next day post-shift (28 observations on 18 workers)
-0.36 ± 0.72 (0.62)
-b
0.047 ± 0.025 (0.082)
0.66 ± 0.12 (<0.0001)
63%

R2, the percent of variance explained by the fixed effects in the model, is estimated by 1 – (estimated total variance for full model/estimated total variance for reduced model), where the reduced model contains only the intercept.

a estimate ± standard error (P-value)

b day effect was not significant and was excluded from the model

McKernan et al. Environmental Health 2008 7:12   doi:10.1186/1476-069X-7-12