. 2019 Apr 3;19:375. doi: 10.1186/s12889-019-6694-4

Table 3.

Multiple linear regression models of nicotine metabolites by job type, Pennsylvania Adult Smoking Study

	Unemployed/Retired/ Student/Disabled				Blue Collar				White Collar
	Est	95% CI		P-value	Est	95% CI		P-value	Est	95% CI		P-value
Nicotine metabolite
Cotinine
Intercept	146.65	−5.84	299.13	0.059	136.21	29.14	243.28	0.013	141.19	−67.92	350.29	0.183
SES PC1	−65.48	− 109.58	−21.38	0.004	13.76	−4.60	32.12	0.141	27.91	−7.87	63.69	0.124
Age	2.73	−0.29	5.75	0.075	3.18	1.31	5.05	0.001	3.64	0.02	7.27	0.049
BMI	−1.85	−6.01	2.30	0.374	−3.16	−6.07	−0.25	0.034	−4.10	−9.82	1.63	0.156
FTND score	6.96	−8.14	22.06	0.359	23.22	13.74	32.69	<.001	27.88	11.35	44.41	0.001
Sex (M vs F)	67.87	−9.70	145.43	0.085	57.57	16.61	98.52	0.006	46.24	−31.31	123.78	0.238
Adj R²	0.279				0.245				0.209
n	57				170				77
3HC^a
Intercept	7.88	2.97	12.80	0.002	7.33	4.66	1.00	<.001	1.58	−2.77	5.92	0.472
SES PC1	0.07	−1.20	1.34	0.915	−0.45	−0.92	0.02	0.059	0.80	0.05	1.55	0.037
Age	0.11	0.02	0.19	0.014	0.07	0.02	0.12	0.006	0.10	0.03	0.18	0.007
FTND score	0.09	−0.38	0.57	0.697	0.38	0.12	0.65	0.005	0.87	0.50	1.24	<.001
Adj R²	0.228				0.230				0.364
n	56				168				78
TSNM^a
Intercept	−1.87	−2.26	−1.49	<.001	−1.73	−1.97	− 1.49	<.001	−2.03	− 2.41	− 1.65	<.001
SES PC1	−0.12	−0.23	0.00	0.042	−0.01	− 0.05	0.03	0.604	0.07	0.01	0.14	0.027
Age	0.01	0.00	0.02	0.047	0.01	0.00	0.01	0.001	0.01	0.00	0.02	0.005
BMI	0.00	−0.01	0.01	0.868	−0.01	−0.02	0.00	0.010	0.00	−0.01	0.01	0.410
FTND score	0.02	−0.02	0.05	0.391	0.06	0.04	0.08	<.001	0.08	0.05	0.11	<.001
Sex (M vs F)	0.15	−0.06	0.35	0.152	0.11	0.02	0.20	0.018	0.04	−0.10	0.18	0.602
Adj R²	0.205				0.2890				0.406
n	55				168				77

Abbreviations: 3HC: 3′-hydroxycotinine, TSNM: Total Salivary Nicotine Metabolites, NMR: Nicotine Metabolite Ratio, CPD: cigarettes per day, BMI: Body mass index, FTND: Fagerström Test for Nicotine Dependence, SES PC1: Socioeconomic status primary principal component

^a3HC and TSNM were log-transformed