Table 2 Results of multiple level model (weighted)

Group

 Gender

  Male

1.00

1.00

1.00

1.00

  Female

0.38 (0.24, 0.65)**

0.40 (0.27, 0.68)**

0.41 (0.26, 0.69)**

0.40 (0.24, 0.67)**

 Monthly expenses

  <1000

1.00

1.00

1.00

1.00

  1000–1499

2.32 (0.70, 7.54)

2.43 (0.72, 7.61)

1.06 (0.66, 1.76)

2.41 (0.73, 7.99)

  1500–1999

1.52 (0.38, 5.86)

1.47 (0.39, 5.85)

1.03 (0.62, 1.81)

1.51 (0.42, 5.49)

  2000 and over

4.07 (1.27, 13.2)**

4.10 (1.29, 13.2)**

2.65 (1.54, 3.35)**

4.23 (1.33, 13.16)*

 Smoking

  Non-smoker

1.00

1.00

1.00

1.00

  Occasional smoker

1.15 (0.56, 2.44)

1.19 (0.55, 2.46)

0.77 (0.37, 1.58)

1.19 (0.57, 2.49)

  Daily smoker

2.12 (1.12, 3.89)*

2.07 (1.14, 3.98)*

1.30 (0.61, 2.84)

2.06 (1.06, 3.99)*

 Family home location

  Rural or township

1.00

1.00

  County town

2.24 (1.36, 2.75)**

2.22 (1.34, 3.61)**

  City

3.79 (1.20, 12.27)*

3.73 (1.15, 12.01)*

 Type of university

  High level

1.00

1.00

  Middle level

0.76 (0.54, 1.15)

1.51 (0.90, 2.45)

  Lower level

0.79 (0.48, 1.39)

1.14 (0.95, 1.36)

GDP per capita of home region

  <50,000

1.00

1.00

  50,000–99,000

1.51 (0.89, 2.51)

1.52 (0.92, 2.54)

  100,00 and over

1.43 (1.05, 1.42)*

1.43 (1.04, 1.42)*

 University city GDP per capita

  <50,000

1.00

1.00

  50,000–

0.92 (070, 1.21)

1.12 (0.55, 2.29)

  100,000–

1.21 (0.66, 1.21)

1.39 (0.55, 3.71)

 City population (million)

  <1.0

1.00

1.00

  1–3.9

1.28 (0.82, 1.93)

1.71 (1.10, 2.68)*

  4 and over

1.41 (0.80, 2.35)

1.48 (1.04, 2.31)*

Fixed parameters

37.36 **

19.12**

17.25**

16.42**

15.75**

Random parameters between universities

4.41**

3.89**

4.25**

2.43*

2.25*

Random parameters between the original provinces

62.04**

39.87**

35.41**

37.82**

15.89**