Table 2

 Comparison of “OTC” NRT users versus non-users among lighter smokers*

Smokers ⩽15 cigarettes/day: “OTC” NRT use
Sample sizeUsed NRT (%)Unadjusted p value OR (95% CI)Adjusted p value† OR (95% CI)Adjusted p value‡ OR (95% CI)
p Values shown are the logistic regression omnibus test of association between all levels of the row variable and NRT use. Odds ratios are pair wise comparisons between category and referent category (initial level where p value noted) from logistic regression. When the confidence limits for the odds ratio do not include 1.0, this indicates that the row category differed significantly in NRT use in comparison to the reference category for that variable.
*This subanalysis was performed to be consistent with Pierce and Gilpin’s analysis of quitting outcomes among light smokers who used or did not use OTC NRT.
†Logistic regression: adjusted for covariates of age (continuous), sex (dichotomised), education (categorical), and smoking rate (continuous).
‡Logistic regression: adjusted for covariates of age (continuous), sex (dichotomised), education (categorical), smoking rate (continuous), and first cigarette within 30 minutes of waking (dichotomised).
Overall sample155416.4%
Demographic characteristics
Age (years)
    18–25 (referent)2089.7<0.001
    26–3531812.01.26 (0.84 to 1.90)
    36–4537022.52.69 (1.82 to 3.99)
    46–5526325.53.18 (2.05 to 4.93)
    56+39521.82.58 (1.64 to 4.07)
Sex
    Female (referent)107215.3<0.167
    Male47617.81.20 (0.93 to 1.54)
Education
    Non-HS graduate (referent)17716.9<0.315
    High school (HS) graduate47916.40.96 (0.63 to 1.47)
    Some college51114.40.83 (0.54 to 1.26)
    Associate degree14318.61.12 (0.65 to 1.93)
    Bachelor degree16021.61.36 (0.81 to 2.26)
    Postgraduate degree7513.70.78 (0.36 to 1.68)
Annual household income
    Under $15000 (referent)35714.0<0.275
    $15000–$2499923415.71.15 (0.74 to 1.78)
    $25000–$3999931015.21.10 (0.73 to 1.65)
    $40000–$5999932817.01.26 (0.85 to 1.87)
    $60000+32519.71.50 (1.02 to 2.21)
Smoking status and history
Cigarettes per day
    10 or less (referent)94713.6<0.001
    11–1419822.21.81 (1.26 to 2.60)
    15–2040920.51.63 (1.22 to 2.18)
    21–30
    31+
Daily smoking
    No (referent)25710.4<0.002<0.395<0.616
    Yes129717.81.87 (1.27 to 2.74)1.21 (0.78 to 1.87)1.12 (0.72 to 1.76)
Years of smoking
    10 or less (referent)31210.6<0.001<0.001<0.001
    11–2034312.21.17 (0.80 to 1.71)1.16 (0.75 to 1.79)1.13 (0.73 to 1.74)
    21–3034125.12.82 (1.98 to 4.04)3.00 (1.68 to 5.34)2.90 (1.63 to 5.17)
    31–4024025.52.88 (1.88 to 4.43)3.09 (1.37 to 6.95)2.80 (1.24 to 6.33)
    41+30623.22.55 (1.62 to 4.00)3.26 (1.03 to 10.38)3.01 (0.95 to 9.59)
Number of quit attempts
    0–2 (referent)44317.6<0.453<0.553<0.480
    3–551914.50.79 (0.58 to 1.09)0.79 (0.57 to 1.10)0.77 (0.55 to 1.07)
    6–1033216.80.95 (0.67 to 1.35)0.92 (0.64 to 1.32)0.91 (0.63 to 1.31)
    11+26017.91.02 (0.69 to 1.51)0.92 (0.62 to 1.37)0.90 (0.60 to 1.35)
Smoking dependence
FTND
    1 or less (referent)48110.8<0.001<0.001<0.015
    1<FTND⩽350715.31.49 (1.06 to 2.11)1.23 (0.84 to 1.80)1.26 (0.81 to 1.96)
    3<FTND⩽539422.42.38 (1.69 to 3.37)1.78 (1.17 to 2.71)1.86 (1.02 to 3.41)
    5<FTND⩽79732.74.01 (2.45 to 6.57)2.92 (1.65 to 5.17)3.06 (1.46 to 6.40)
    7<FTND
Time to first cigarette
    After 60 minutes (referent)47410.6<0.001<0.007
    31–60 minutes32115.71.57 (1.06 to 2.31)1.30 (0.87 to 1.95)
    6–30 minutes59519.62.06 (1.48 to 2.85)1.53 (1.06 to 2.20)
    Within 5 minutes14927.33.16 (2.03 to 4.90)2.32 (1.43 to 3.75)
NDSS-T
    −3 or less (referent)27611.2<0.001<0.001<0.003
    −3<NDSS⩽−1.541612.51.13 (0.72 to 1.77)0.88 (0.55 to 1.42)0.84 (0.52 to 1.36)
    −1.5<NDSS⩽030118.91.84 (1.18 to 2.86)1.51 (0.94 to 2.41)1.43 (0.89 to 2.30)
    0<NDSS⩽1.520219.81.95 (1.22 to 3.13)1.64 (0.98 to 2.75)1.52 (0.91 to 2.57)
    1.5<NDSS13528.73.19 (1.95 to 5.20)2.47 (1.44 to 4.23)2.14 (1.23 to 3.73)
Craving (at last quit)
    Not present/mild (1,2; referent)60912.9<0.002<0.044<0.115
    Moderate (3)63416.71.34 (1.00 to 1.81)1.11 (0.82 to 1.52)1.10 (0.81 to 1.50)
    Severe (4)29121.91.89 (1.34 to 2.65)1.56 (1.09 to 2.24)1.46 (1.01 to 2.10)
Withdrawal (at last quit)
    1.3 or less (referent)3567.8<0.001<0.001<0.001
    1.3<WD⩽256314.82.04 (1.33 to 3.12)1.87 (1.21 to 2.90)1.78 (1.15 to 2.77)
    2<WD⩽344321.73.26 (2.13 to 5.00)3.07 (1.98 to 4.76)2.88 (1.85 to 4.50)
    3<WD17226.74.29 (2.61 to 7.06)3.71 (2.21 to 6.22)3.43 (2.03 to 5.78)
Difficulty in quitting
    2 or less (referent)1624.6<0.001<0.001<0.001
    2<Diff⩽53258.31.85 (0.85 to 4.01)1.56 (0.71 to 3.42)1.48 (0.67 to 3.25)
    5<Diff⩽73419.22.08 (0.97 to 4.43)1.82 (0.85 to 3.93)1.79 (0.83 to 3.85)
    7<Diff⩽943021.55.61 (2.74 to 11.49)4.58 (2.21 to 9.50)4.41 (2.13 to 9.16)
    9<Diff⩽1029636.511.81 (5.73 to 24.32)9.24 (4.42 to 19.32)8.72 (4.16 to 18.29)
Medical and psychiatric history
Smoking related disease
    Not reported (referent)54215.5<0.007<0.170<0.139
    Reported60021.41.49 (1.12 to 1.98)1.25 (0.91 to 1.71)1.27 (0.93 to 1.74)
Psychiatric condition
    Not reported (referent)29619.5<0.475<0.756<0.526
    Reported84617.70.89 (0.63 to 1.24)0.94 (0.66 to 1.34)0.89 (0.63 to 1.27)