Table 3

Adjusted odds ratio for factors associated with initiation of injection

Adjusted odds ratio (95% CI)

Age

Under 20 years old

Reference

20~29 years old

4.3 (2.7~6.8)

30~39 years old

6.0 (3.6~10.2)

40 years old or older

5.3 (3.0~9.3)

Male

Thai ethnicity

Single

1.7 (1.3~2.2)

Rural residence

0.50 (0.37~0.66)

Education

No schooling

Reference

≤ 6 years

1.7 (1.2~2.3)

7~11 years

1.8 (1.2~2.7)

12 or more years

1.5 (1.0~2.3)

Employed

Ever smoking

2.9(1.5~5.3)

Ever drinking

Ever in jail

5.0 (4.0~6.4)

No. of lifetime sex partners

One or no partner

Reference

2~5 partners

1.1 (0.83~1.6)

6~10 partners

1.5 (1.0~2.2)

11 or more partners

1.9 (1.4~2.7)

Ever selling sex

Ever sex abused

3.3 (1.2~9.1)

Type of initiation drug

Opium

Reference

Marijuana

0.98 (0.68~1.4)

Heroin

2.7 (1.9~3.8)

Amphetamine

0.098 (0.057~0.17)

Others

1.2 (0.70~2.1)

Age of drug initiation

Under 16 years old

Reference

16~18 years old

0.83 (0.60~1.1)

19~23 years old

0.56 (0.39~0.79)

24 years old or older

0.25 (0.16~0.37)

Cheng et al. Harm Reduction Journal 2006 3:10   doi:10.1186/1477-7517-3-10