Table 1. The assignments of each covariable.
| Variables | Assignments |
| Age (years) | Continuous variable |
| Sex | Male=0; female=1 |
| BMI (kg/m2)a | 18.5‐23.9 (normal weight)=0; <18.5 (underweight)=1; 24.0‐27.9 (overweight)=2; ≥28.0 (obesity)=3 |
| Educationa | Illiterate=0; primary school=1; junior middle school=2; senior middle school or more=3 |
| Marital statusa | Married=0; unmarried=1; divorced/widowed=2 |
| Average income (¥)a,b | Less than 5000=0; 5000‐9999=1; 10,000‐29,999=2; 30,000 or more=3 |
| Residence | Rural=0; urban =1 |
| Physical activity | No=0; yes=1 |
| Smoking | No=0; yes=1 |
| Drinking | No=0; yes=1 |
| Self-reported disease | No=0; yes=1 |
| Self-reported injury | No=0; yes=1 |
a
Entered into the regression model as the dummy variable.
b
A currency exchange rate of ¥1=US $0.14 is applicable.