Table 6 Odds ratios and 95% confidence intervals (CI) of a multinomial logit model for the choice of using self-treatment, seeking professional medical services, or doing nothing (reference)

Survey year:1993 (reference)

 1998

2.19 (1.84–2.62)**

0.87(0.75-1.01)

 2003

2.37(1.98-2.83)**

0.54(0.46-0.62)**

 2008

1.98(1.64-2.39)**

0.49(0.41-0.58)**

 Urban:Rural (reference group)

1.32(1.21-1.44)**

0.90(0.83-0.98)*

Age: 15–24 years old (=reference group)

 25-44 years old

0.92(0.82-1.03)

0.83(0.74-0.93)**

 45-64 years old

0.99(0.88-1.12)

0.74(0.66-0.83)**

 >65 years old

1.01(0.89-1.15)

0.80(0.71-0.90)**

Education: Illiterate or semi-illiterate(=reference group)

 Primary or junior school

1.17(1.10-1.24)**

1.09(1.03-1.15)**

 High or technical school

1.20(1.08-1.33)**

1.06(0.97-1.18)

 College or university and above

1.09(0.92-1.27)

1.03(0.88-1.21)

Profession: Unemployed (=reference group)

 Worker

1.22(1.10-1.35)**

1.27(1.15-1.40)**

 Farmer

0.85(0.79-0.92)**

1.15(1.07-1.24)**

 Retired

1.13(0.99-1.29)

1.28(1.12-1.47)**

Family members: 1–2 person (=reference group)

 3-4 persons

1.29(1.16-1.45)**

1.24(1.12-1.39)**

 ≥5 persons

1.39(1.24-1.56)**

1.57(1.41-1.76)**

Insurance: Without insurance(=reference group)

 Other medical insurance

0.97(0.82-1.15)

1.36(1.15-1.61)**

 Rural cooperative medical scheme

0.87(0.80-0.94)**

1.05(0.98-1.14)

 Urban basic medical insurance

1.03(0.93-1.15)

1.25(1.12-1.40)**

 Free medical insurance

1.45(1.22-1.72)**

1.65(1.39-1.95)**

 Shortest distances from residence at medical institutions:≤1 km (=reference group)

0.83(0.79-0.88)**

0.82(0.78-0.86)**

 Sanitary water: No (=reference group)

1.15(1.08-1.22)**

0.86(0.82-0.91)**

Annual per capita income^a: Low(=reference group)

 Middle

1.53(1.44-1.63)**

1.46(1.38-1.55)**

 High

1.59(1.47-1.72)**

1.72(1.59-1.85)**

 Smoking:No (=reference group)

1.01(0.95-1.08)

0.91(0.86-0.97)**

 Drinking:No (=reference group)

0.92(0.86-1.0)*

0.84(0.78-0.90)**

 Exercising: No (=reference group)

1.23(1.14-1.33)**

1.22(1.13-1.32)**

 Limited activity: No (=reference group)

0.84(0.78-0.90)**

0.96(0.90-1.13)**

 Chronic disease: No (=reference group)

1.21(1.14-1.27)**

0.86(0.82-0.91)**

Duration within two week:1-2 day (=reference group)

 3-4 day

1.32(1.24-1.41)**

1.87(1.76-2.0)**

 ≥5 day

1.0 (0.94-1.07)

1.62(1.52-1.72)**

 Constant

−0.68(0.12)**

1.03(0.11)**