Table 4 Weighted multivariable logistic regression models of multiple sexual partners, casual sex, group sex, and rare condom use on early sexual initiation among alcohol- and tobacco-using young adults in Taipei metropolitan area recruited using RDS during 2007–2010 (N = 916)

Variable

aOR

95% CI

aOR

95% CI

aOR

95% CI

aOR

95% CI

aOR

95% CI

Age/years since sexual initiation^c

1.04*

(1.01–1.07)

1.07***

(1.03–1.10)

0.99

(0.96–1.01)

1.01

(0.97–1.05)

1.00

(0.97–1.04)

Education level < college

1.00

(0.59–1.70)

0.92

(0.53–1.58)

1.01

(0.66–1.55)

0.91

(0.43–1.92)

3.90***

(2.25–6.76)

 Full-time job

2.19*

(1.16–4.16)

2.04*

(1.06–3.92)

1.38

(0.84–2.28)

1.67

(0.70–3.99)

0.96

(0.51–1.82)

 Unemployed/part-time job/military

1.49

(0.61–3.65)

1.22

(0.47–3.14)

1.56

(0.76–3.19)

2.05

(0.65–6.45)

1.19

(0.53–2.65)

Living with marital or romantic partner

0.79

(0.43–1.42)

0.73

(0.40–1.31)

1.59*

(1.01–2.51)

1.48

(0.68–3.25)

0.91

(0.52–1.61)

Homosexual/bisexual experience

3.24**

(1.61–6.52)

3.22**

(1.55–6.69)

1.85*

(1.02–3.36)

3.11**

(1.52–6.39)

1.84

(0.89–3.81)

 Male, non-early sexual initiation

7.72***

(3.89–15.34)

7.94***

(3.90–16.15)

3.66***

(2.27–5.90)

3.25*

(1.28–8.24)

0.60

(0.35–1.03)

 Female, early sexual initiation

8.78**

(2.54–30.31)

8.14**

(2.41–27.48)

8.35***

(2.95–23.59)

6.58**

(1.62–26.68)

2.95

(0.99–8.77)

 Male, early sexual initiation

12.63***

(5.08–31.41)

9.93***

(3.77–26.16)

5.24***

(2.55–10.75)

9.85***

(3.63–26.76)

0.57

(0.25–1.33)