Table 2.

Mean (SD) of continuous variables by wave I smoking stage among original population of size n = 11 107 426.^†

	Wave I smoking stage
Covariates	Puffer	Light	Occasional	Regular	Ex-smoker
Age (years)
Overall	15.81 (1.76)	15.98 (1.72)	16.14 (1.65)	16.93 (1.47)	16.34 (1.59)
Recant = no	15.72 (1.77)	15.89 (1.77)	16.13 (1.64)	16.93 (1.46)	16.33 (1.68)
Recant = yes	16.24 (1.78)	16.21 (1.71)	16.21 (1.63)	16.93 (1.58)	16.37 (1.37)
P-value	0.004**	0.033*	0.600	0.991	0.897
Income (thousands of dollars)
Overall	42.56 (38.50)	44.68 (34.03)	48.26 (49.54)	40.18 (36.17)	44.56 (35.76)
Recant = no	43.49 (39.91)	46.06 (32.18)	49.88 (50.87)	40.64 (36.77)	44.50 (35.38)
Recant = yes	37.64 (29.50)	40.85 (38.45)	38.08 (38.71)	31.72 (20.68)	45.39 (40.96)
P-value	0.047*	0.143	0.004**	0.096	0.937
Depression (wave I)
Overall	5.36 (3.89)	6.00 (4.22)	6.84 (4.51)	7.24 (4.71)	6.20 (4.56)
Recant = no	5.24 (3.92)	5.79 (4.06)	6.70 (4.50)	7.24 (4.75)	6.08 (4.59)
Recant = yes	5.96 (3.68)	6.59 (4.55)	7.75 (4.41)	7.22 (3.78)	7.43 (3.85)
P-value	0.020*	0.012*	0.004**	0.970	0.143
Depression (wave III)
Overall	4.54 (4.08)	4.45 (3.92)	5.00 (4.27)	4.57 (4.34)	5.06 (4.77)
Recant = no	4.56 (4.08)	4.47 (3.92)	4.90 (4.24)	4.62 (4.36)	5.06 (4.60)
Recant = yes	4.45 (4.07)	4.40 (3.93)	5.63 (4.33)	3.52 (3.95)	5.10 (6.15)
P-value	0.754	0.803	0.058	0.171	0.974
Depression (wave III–I)
Overall	−0.82 (4.49)	−1.55 (4.76)	−1.84 (5.10)	−2.67 (5.34)	−1.14 (5.21)
Recant = no	−0.68 (4.43)	−1.31 (4.70)	−1.79 (5.03)	−2.62 (5.39)	−1.02 (5.18)
Recant = yes	−1.51 (4.71)	−2.19 (4.88)	−2.12 (5.51)	−3.70 (4.27)	−2.33 (5.33)
P-value	0.032*	0.010*	0.535	0.201	0.271

^*P < 0.05;

^**P < 0.01

^†P-values for mean differences between recanters and non-recanters calculated using survey estimation commands in Stata 9.0 (StataCorp. [22]).