TABLE 3.

Weighted Logistic Regression Model of Ever Experimenting Among California Non-Hispanic White Male Adolescents and Adults: California Tobacco Survey, 1990–2005

Model Variables	Coefficient (95% CI)	Between-Group Comparisons From Model	OR (95% CI)
Intercept	−1.86 (−1.97, −1.74)
Cohort indicators (cumulative)		Comparing successive cohorts
Born 1976–1993 (Ref)	1.00	Cohort 1976–1978	1.00
Born 1979–1993	NS	Cohort 1979–1981 versus cohort 1976–1978	NS
Born 1982–1993	NS	Cohort 1982–1984 versus cohort 1979–1981	NS
Born 1985–1993	−0.51 (−0.75, −0.27)	Cohort 1985–1987 versus cohort 1982–1984	0.60 (0.47, 0.76)
Born 1988–1993	−0.85 (−1.19, −0.52)	Cohort 1988–1990 versus cohort 1985–1987	0.43 (0.30, 0.59)
Born 1991–1993	NS	Cohort 1991–1993 versus cohort 1988–1990
Age indicators (cumulative)		Comparing successive ages (main effects)
12–26 y (Ref)	1.00	Age 12–14 y	1.00
15–26 y	1.60 (1.42, 1.78)	Age 15–17 y versus age 12–14 y	4.95 (4.14, 5.93)a
18–26 y	0.89 (0.68, 1.09)	Age 18–20 y versus age 15–17 y	2.44 (1.97, 2.97)
21–26 y	0.42 (0.11, 0.73)	Age 21–23 y versus age 18–20 y	1.52 (1.12, 2.08)a
24–26 y	−0.30 (−0.64, 0 04)	Age 24–26 y versus age 21–23 y	0.74 (0.53, 1.04)
Interaction terms		Comparing successive ages (interaction)
Born 1982–1993 × age 15–26 y	−0.36 (−0.56, −0.16)	Age 15–17 y versus age 12–14 y; born < 1982 versus born ≥ 1982	0.70 (0.57, 0.85)
Born 1982–1993 × age 21–26 y	0.37 (−0.17, 0.92)	Age 21–23 y versus age 18–20 y; born < 1982 versus born ≥ 1982	1.45 (0.84, 2.51)

Note. CI = confidence interval; NS = not significant; OR = odds ratio. Terms not significant at P < .25 were dropped from the model using backward selection, starting from a fully parameterized model. Estimates are weighted to be representative of the population.

^aOdds ratio for cohorts born before 1982. For cohorts born 1982 or later, multiply by appropriate interaction OR.