Table 2 Cox’s proportional hazards model analyses on factors associated with MMT retention duration

Age group(year)( ≤30=0)

>30

1

0.69**

0.62~0. 77

0.78**

0.69~0.88

Residence(urban=0)

rural

1

1.25**

1.20~1.30

1.12*

1.01~1.25

income(others=0)

family or friends

1

0.19**

0.17~0.21

0.40**

0.31~0.52

fixed income

2

0.21**

0.18~0.24

0.40**

0.30~0.54

temporary income

3

0.20**

0.18~0.22

0.43**

0.33~0.55

social welfare

4

0.17**

0.11~0.26

0.41**

0.23~0.72

Living with family or friends(yes=0)

other

1

5.50**

4.84~6.23

Relationship with family(bad=0)

good

1

0.31**

0.29~0.34

0.68**

0.58~0.80

Drug use years pre-admission(years) (>10=0)

≤5

1

1.14*

1.02~1.28

6~10

2

1.13**

1.04~1.23

Sharing needles(no=0)

yes

1

1.25**

1.12~1.39

1.23*

1.08~1.40

Considering treatment cost suitable(no=0)

yes

1

0.35**

0.32~0.38

0.71**

0.60~0.84

Considering treatment operation time suitable(no=0)

yes

1

0.27**

0.25~0.30

0.73**

0.62~0.87

Daily expense for drug (RMB¥)prior to MMT(>300=0)

≤300

1

1.21**

1.10~1.33

0. 80**

0.71~0.90

Re-enrolled(no=0)

yes

1

1.49**

1.42~1.56

1.41**

1.34~1.49

History of being arrested(no=0)

yes

5.43**

4.96~5.96

1.35**

1.08~1.69

Daily treatment dosage(mg)(>50=0)

≤30

1

1.25**

1.14~1.38

1.44**

1.29~1.61

31~50

2

1. 27**

1.17~1.39

1.33**

1.21~1.48

Communication with former drug taking peers last month(yes=0)

no

1

0.60**

0.57~0.63

0.90**

0.84~0.98

Satisfaction with MMT service(no=0)

yes

1

0.23**

0.20~0.25