Table 3 Bivariate t-tests and Chi-square tests of predictor variables in 2014 and support in 2015^a,b

  Male (%)

40.2

59.8

χ² = 0.43

  Female (%)

40.9

59.1

p = 0.836

  15-24 years (%)

34.1

65.9

χ² = 3.91

  25-39 years (%)

45.8

54.2

p = 0.271

  40-54 years (%)

39.1

60.9

  55 years and older (%)

40.4

59.6

 Low (%)

38.8

61.2

χ² = 0.77

 Moderate (%)

39.3

60.7

p = 0.681

 High (%)

43.3

56.7

 Knowledge health risks of smoking (mean, SD)

0.65 (0.27)

0.54 (0.30)

t = −5.62, p < 0.001

 Noticing anti-tobacco information (mean, SD)

2.41 (0.96)

2.29 (0.95)

t = −1.57, p = 0.116

 Perceived susceptibility (mean, SD)

3.14 (0.96)

3.09 (0.84)

t = −0.82, p = 0.413

 Perceived severity (mean, SD)

3.54 (1.03)

3.16 (0.99)

t = −5.42, p < 0.001

 Attitude towards quitting smoking (mean, SD)

4.21 (0.70)

3.86 (0.79)

t = −6.80, p < 0.001

 Social norms for quitting smoking(mean, SD)

4.41 (0.74)

4.10 (0.77)

t = −5.73, p < 0.001

 Self-efficacy for quitting smoking (mean, SD)

2.45 (1.07)

2.23 (1.00)

t = − 2.95, p = 0.003

Intention to quit smoking (mean, SD)

2.77 (1.15)

2.32 (1.06)

t = − 5.85, p < 0.001