Table 1

Descriptive data for the sample (n=3994)

n
(%)
Gender
 Male1904 (47.7)
 Female2090 (52.3)
Ethnicity
 White688 (17.2)
 Non-white3306 (82.8)
Family affluence12.72 (0.49)
Ever used e-cigarettes (baseline)
 No3236 (81.0)
 Yes758 (19.0)
Friend smokers
 None2602 (65.1)
 A few or more1392 (34.9)
Family smokers
 None1502 (37.6)
 One or more2492 (62.4)
Impulsivity*2.04 (1.65)
Intention
 Low3624 (90.7)
 High370 (9.3)
Attitude
 Low3302 (82.7)
 High692 (17.3)
Norms
 Low3455 (86.5)
 High539 (13.5)
Perceived behavioural control
 Low3260 (81.6)
 High734 (18.4)
Self-efficacy
 Low3239 (81.1)
 High755 (18.9)
Free school meals†
 Low22 (48.9)
 High23 (51.1)
Condition†
 Control20 (44.4)
 Intervention25 (55.6)
Ever smoked cigarettes (follow-up)
 No3180 (79.6)
 Yes814 (20.4)
Any recent tobacco smoking (follow-up)
 No3607 (90.3)
 Yes387 (9.7)
Regularly smoked cigarettes (follow-up)
 No3910 (97.9)
 Yes84 (2.1)
  • *Mean and SD for these variables.

  • †Number of schools.