Table 4

Associations between living in e-cigarette sales restriction (ESR) localities at baseline and e-cigarette use at follow-up, stratified by cigarette smoking at baseline, among e-cigarette users (18–21 years; N=435)

E-cigarette use at follow-up*
All
participants		Cigarette smokersNon-cigarette smokersAll
participants		Cigarette smokersNon-cigarette smokers
 N=435N=90N=345N=435N=90N=345
ESR policy category 1
 Without ESRsReferenceReferenceReferenceNot applicable
 With any ESRs 1.69 (1.09 to 2.65) 5.65 (1.62 to 19.64)1.49 (0.90 to 2.48)
ESR policy category 2
 Without ESRNot applicableReferenceReferenceReference
 With flavoured ESRs 1.71 (1.02 to 2.87) 6.40 (1.53 to 26.74)1.51 (0.83 to 2.74)
 With comprehensive ESRs1.65 (0.85 to 3.20)4.25 (0.62 to 29.08)1.47 (0.69 to 3.11)
Age
 18 and 19ReferenceReferenceReferenceReferenceReferenceReference
 20 and 210.86 (0.56 to 1.45)2.10 (0.53 to 8.35)0.72 (0.40 to 1.31)0.86 (0.51 to 1.45)2.09 (0.52 to 8.35)0.72 (0.40 to 1.31)
Gender†
 FemaleReferenceReferenceReferenceReferenceReferenceReference
 Male1.16 (0.74 to 2.12)1.50 (0.41 to 5.45)1.02 (0.61 to 1.71)1.15 (0.73 to 1.82)1.42 (0.38 to 5.29)1.02 (0.61 to 1.71)
Sexual orientation
 HeterosexualReferenceReferenceReferenceReferenceReferenceReference
 Other‡1.24 (0.73 to 2.12)2.83 (0.72 to 11.05)1.10 (0.60 to 2.04)1.25 (0.74 to 2.14)4.45 (0.97 to 20.41)1.11 (0.60 to 2.05)
Race and ethnicity
 Hispanic0.72 (0.39 to 1.36)0.41 (0.11 to 1.53)1.01 (0.48 to 2.23)0.73 (0.39 to 1.36)0.41 (0.11 to 1.54)1.02 (0.47 to 2.21)
 Non-Hispanic whiteReferenceReferenceReferenceReferenceReferenceReference
 Non-Hispanic Asian0.94 (0.45 to 1.96)0.60 (0.07 to 5.03)1.28 (0.56 to 2.98)0.96 (0.44 to 2.04)0.63 (0.07 to 5.28)1.30 (0.54 to 3.13)
 Non-Hispanic other§1.16 (0.52 to 2.57)0.49 (0.07 to 3.47)1.54 (0.62 to 3.89)1.17 (0.52 to 2.64)0.46 (0.06 to 3.39)1.56 (0.60 to 4.07)
Education level†
 ≤High schoolReferenceReferenceReferenceReferenceReferenceReference
 ≥Some college0.91 (0.58 to 1.41)0.67 (0.21 to 2.09)0.86 (0.52 to 1.44)0.91 (0.58 to 1.41)0.64 (0.20 to 2.05)0.85 (0.52 to 1.41)
Subjective financial status†
 <Living comfortably¶ReferenceReferenceReferenceReferenceReferenceReference
 Living comfortably0.89 (0.58 to 1.36)1.08 (0.37 to 3.18)0.83 (0.51 to 1.36)0.89 (0.58 to 1.37)1.07 (0.36 to 3.15)0.84 (0.51 to 1.37)
Current e-cigarette use frequency
 1–2 daysReferenceReferenceReferenceReferenceReferenceReference
 3–9 days 1.75 (1.02 to 3.01)2.56 (0.56 to 11.69)1.68 (0.92 to 3.07) 1.76 (1.02 to 3.02)2.55 (0.56 to 11.58)1.68 (0.92 to 3.07)
 10–30 days 2.79 (1.63 to 4.77)1.62 (0.48 to 7.15) 3.28 (1.79 to 5.98) 2.80 (1.64 to 4.78)1.53 (0.34 to 6.70) 3.28 (1.79 to 6.02)
Current e-cigarette dependence
 Yes 1.86 (1.15 to 3.02)1.44 (0.46 to 4.46) 2.17 (1.23 to 3.81) 1.87 (1.15 to 3.02)1.50 (0.47 to 4.78) 2.17 (1.23 to 3.81)
 NoReferenceReferenceReferenceReferenceReferenceReference
Current cigarette smoking
 Yes1.46 (0.84 to 2.53)Not applicable1.46 (0.83 to 2.52)Not applicable
 NoReference

  • *Bolded text indicates statistical significance (p<0.05).

  • †‘Other’ or ‘undetermined’ categories for gender, education level and subjective financial status were omitted due to small cells and wide CIs.

  • ‡‘Other’ category for sexual orientation includes asexual, bisexual, gay, lesbian, pansexual, queer, questioning or unsure, and other identities.

  • §‘Other’ category for race/ethnicity includes American Indian or Alaska Native, Native Hawaiian or Pacific Islanders.

  • ¶<Living comfortably category includes met needs with a little left, just meet basic expenses and do not meet basic expenses.