Table 2 Logistic regression estimates (OR) of predictors of health risk behaviours [OR (95 % CI), n = 471]

Best friend is smoking

16.7 (9.79-28.5)***

3.1 (2.02-4.74)***

2.08 (1.4-3.08)***

Best friend drinks alcohol

5.28 (2.85-9.8)***

24.2 (13.9-42.2)***

7.51 (3.75-15)***

Friends’ smoking

 None/Minority of friends

1

1

1

 Half of friends

4.01 (2.32-6.95)***

2.11 (1.24-3.59)**

2.67 (1.61-4.44)***

 Majority/All of friends

13.7 (7.93-23.6)***

3.86 (2.17-6.91)***

2.93 (1.81-4.74)***

Friends’ alcohol use

 None/Minority of friends

1

1

1

 Half of friends

1.73 (0.96-3.11)

2.93 (1.42-6.02)**

1.7 (0.95-3.05)

 Majority/All of friends

1.84 (1.14-2.97)*

4.35 (2.27-8.31)***

2.87 (1.75-4.70)***

Loneliness (cont.)

0.95 (0.92-0.98)**

0.95 (0.93-0.98)**

0.98 (0.95-1.02)

Shyness (cont.)

0.97 (0.95-0.99)*

0.97 (0.95-0.99)*

0.97 (0.95-0.99)*

Need to belong (cont.)

0.98 (0.94-1.01)

1 (0.96-1.03)

1 (0.93-1.03)

Competitiveness (cont.)

1 (0.99-1.03)

1.01 (0.99-1.04)

1.01 (0.98-1.02)

Gender

 Girl^a

1

1

1

 Boy

1 (0.67-1.49)

1.99 (1.29-3.07)**

1.57 (1.04-2.37)

Age (cont.)

1.24 (1.04-1.48)*

1.45 (1.21-1.74)***

1.12 (0.94-1.33)