Table 2 Estimated Odds Ratios (OR) and 95% Confidence Intervals (CI) in Adjusted and Unadjusted Logistic Regression Models for THC Positivity in Blood given Oral Fluid Concentration (ng/ml), Continental United States, Nighttime Weekend and Daytime Friday, 2013–2014
|  | Model 1 (n = 4596) | Model 2 (n = 4433) | Model 3 (n = 4415) |
|---|---|---|---|
OR (95% CI) | OR (95% CI) | OR (95% CI) | |
Positive oral fluid test result | 28.46 (13.86, 58.46) | 12.10 (5.15, 28.41) | 11.36 (7.32, 17.65) |
Log(oral fluid THC) (log-ng/ml) | 1.82 (1.48, 2.24) | 1.93 (1.51, 2.47) | 1.91 (1.68, 2.17) |
Blood alcohol concentration (ng/dl) | |||
 0 |  | Ref | Ref |
 1–39 |  | 0.88 (0.20,3.82) | 0.85 (0.39, 1.82) |
 40+ |  | 0.19 (0.05, 0.72) | 0.19 (0.10, 0.38) |
Last time used marijuana | |||
 Over a year/Never |  | Ref | Ref |
 Over a Month |  | 3.87 (2.26, 6.61) | 3.91 (2.95, 5.16) |
 Past 2 days to a month |  | 8.78 (5.40, 14.26) | 8.78 (6.81, 11.33) |
 Past 24 Hours |  | 25.16 (14.26, 44.41) | 26.44 (19.64, 34.59) |
Age (years) | |||
 16–20 |  |  | Ref |
 21–34 |  |  | 1.27 (0.96, 1.68) |
 35–54 |  |  | 1.16 (0.84, 1.59) |
  ≥ 55 |  |  | 0.96 (0.63, 1.45) |
Gender (Male vs. Female) | Â | Â | 0.99 (0.81, 1.20) |
Race | |||
 Black |  |  | Ref |
 White |  |  | 0.57 (0.46, 0.71) |
 Other Race |  |  | 0.69 (0.52, 0.91) |
AUC (95% CI) | 0.87 (0.82, 0.91) | 0.94 (0.91, 0.97) | 0.95 (0.92, 0.98) |