Table 3 Frequencies, percentages, crude and adjusted odds of being in the outcome group of interest using three-level mixed-effect logistic regression models
Totaln (%)Crude analysisAdjusted analysis
OR (95% CI)p ValueOR (95% CI)p Value
Susceptible to initiation
Store visit frequency:<0.001<0.001
    At least daily1603503 (31.4)2.0 (1.7 to 2.4)1.8 (1.6 to 2.2)
    Two to three times/week63652038 (32.0)2.1 (1.9 to 2.4)1.9 (1.7 to 2.2)
    Weekly42921075 (25.0)1.5 (1.3 to 1.7)1.4 (1.3 to 1.6)
    Less than weekly2288409 (17.9)1.0 (reference)1.0 (reference)
Notice cigarettes frequency:<0.001<0.001
    Every time35231138 (32.3)2.3 (2.0 to 2.7)2.0 (1.7 to 2.3)
    Most times30181006 (33.3)2.5 (2.1 to 2.8)2.2 (1.9 to 2.5)
    Sometimes3008869 (28.9)2.0 (1.7 to 2.3)1.8 (1.6 to 2.1)
    Hardly ever2554617 (24.2)1.6 (1.3 to 1.8)1.5 (1.3 to 1.7)
    Never2059328 (15.9)1.0 (reference)1.0 (reference)
Experimented
Store visit frequency:<0.001<0.001
    At least daily34251805 (52.7)4.4 (3.9 to 5.0)2.7 (2.4 to 3.1)
    Two to three times/week103293919 (37.9)2.6 (2.3 to 2.8)2.0 (1.8 to 2.2)
    Weekly57041396 (24.5)1.4 (1.3 to 1.6)1.4 (1.2 to 1.6)
    Less than weekly2835528 (18.6)1.0 (reference)1.0 (reference)
Notice cigarettes frequency:<0.001<0.001
    Every time63212769 (43.8)2.1 (1.9 to 2.3)1.5 (1.3 to 1.7)
    Most times46971666 (35.5)1.6 (1.4 to 1.8)1.3 (1.2 to 1.5)
    Sometimes43351310 (30.2)1.3 (1.1 to 1.4)1.1 (1.0 to 1.3)
    Hardly ever36661100 (30.0)1.3 (1.2 to 1.5)1.2 (1.1 to 1.4)
    Never2710633 (23.4)1.0 (reference)1.0 (reference)
Current smoker*
Store visit frequency:<0.001
    At least daily47591249 (26.2)4.1 (3.4 to 4.9)*
    Two to three times/week119311434 (12.0)1.9 (1.6 to 2.3)*
    Weekly6260461 (7.4)1.3 (1.1 to 1.6)*
    Less than weekly3052170 (5.6)1.0 (reference)*
Notice cigarettes frequency:<0.001<0.001
    Every time84181978 (23.5)6.6 (5.3 to 8.1)3.5 (2.8 to 4.4)
    Most times5373607 (11.3)3.1 (2.5 to 3.8)2.2 (1.7 to 2.8)
    Sometimes4797384 (8.0)2.2 (1.7 to 2.8)1.8 (1.4 to 2.3)
    Hardly ever3911187 (4.8)1.3 (1.0 to 1.6)1.2 (0.9 to 1.6)
    Never2869102 (3.6)1.0 (reference)1.0 (reference)
  • Susceptibility to initiation: interaction between Store visit frequency and Notice cigarettes frequency non-significant (p = 0.76); interaction between Store visit frequency and SES non-significant (p = 0.08); and interaction between Notice cigarettes frequency and SES non-significant (p = 0.20). In adjusted analyses, p values for confounders were: ethnicity (p<0.001), parental smoking (p = 0.98), peer smoking (p<0.001), smoking in the home (p<0.001), gender (p<0.001), age (p = 0.25) and SES (p<0.001). Experimental smoking: interaction between Store visit frequency and Notice cigarettes frequency non-significant (p = 0.06); interaction between Store visit frequency and SES non-significant (p = 0.09); and interaction between Notice cigarettes frequency and SES non-significant (p = 0.13). In adjusted analyses, p values for confounders were: ethnicity (p<0.001), parental smoking (p<0.001), peer smoking (p<0.001), smoking in the home (p<0.001), gender (p = 0.83), age (p<0.001) and SES (p = 0.75). Current smoking: interaction between Store visit frequency and Notice cigarettes frequency significant (p = 0.02) but relatively small; interaction between Store visit frequency and SES significant (p<0.001); and interaction between Notice cigarettes frequency and SES non-significant (p = 0.26). In adjusted analyses, p values for confounders were: ethnicity (p<0.001), parental smoking (p<0.001), peer smoking (p<0.001), smoking in the home (p<0.001), gender (p<0.001), age (p<0.001), SES (p = 0.001) and interaction between Store visit frequency and SES significant (p<0.001).

  • *Note that table 4 includes the main effect and interaction terms of SES, so this does not appear in table 3.

  • SES, socioeconomic status.