Table 5.

Logistic Regression Analyses Testing Incremental Validity for Assessment of Cocaine Use

	All Participants (n=1125)				White Participants (n=736)				Black Participants (n=341)
Step 1	Model fit χ2 (2) = 159.25***, R2 = 0.48				Model fit χ2 (2) = 53.82***, R2 = 0.43				Model fit χ2 (2) = 71.26***, R2 = 0.47
	β	S.E.	Odds Ratio	Odds Ratio 95% CI	β	S.E.	Odds Ratio	Odds Ratio 95% CI	β	S.E.	Odds Ratio	Odds Ratio 95% CI
Self-Report	4.56***	0.44	95.69	40.34–226.97	4.75***	0.70	115.13	29.23–453.47	4.17***	0.65	64.68	17.98–232.67
Step 2	Model fit χ2 (4) = 169.92***, R2 = 0.51 Δ χ2 (2) = 10.66**				Model fit χ2 (4) = 63.96***, R2 = 0.51 Δ; χ2 (2) = 10.14**				Model fit χ2 (4) = 76.35***, R2 = 0.50 Δ χ2 (2) = 5.09
	β	S.E.	Odds Ratio	Odds Ratio 95% CI	β	S.E.	Odds Ratio	Odds Ratio 95% CI	β	S.E.	Odds Ratio	Odds Ratio 95% CI
Self-Report	3.40***	0.55	30.02	10.24–88.03	4.04***	0.83	56.56	11.11–288.03	3.31***	0.80	27.48	5.76–131.10
Urine	0.62	0.45	1.85	0.76–4.49	−1.48	0.92	0.23	0.04–1.39	1.12	0.60	3.05	0.95–9.80
Hair	1.43*	0.60	4.16	1.29–13.47	2.63**	0.85	13.86	2.62–73.37	0.63	0.99	1.87	0.27–12.95

Notes.

^*P < .05.

^**P < .01.

^***P < .001.

R² values are Nagelkerke.