Table 2 Equilibrium test results before and after covariate matching.
| Â | Â | Before matching | After matching | ||
|---|---|---|---|---|---|
S.E of D-value1 | P | S.E of D-value1 | P | ||
Family size |  | 12.222 | 0.047 | −2.409 | 0.221 |
Gender | Â | 5.026 | 0.400 | 1.529 | 0.467 |
Ethnic |  | −2.215 | 0.712 | 0.795 | 0.564 |
Age | Â | 0.870 | 0.884 | 3.521 | 0.340 |
Education |  | −15.272 | 0.011 | −4.244 | 0.222 |
Marital status |  | −0.462 | 0.938 | −0.752 | 0.317 |
Length of residence | Â | 5.737 | 0.344 | 6.046 | 0.199 |
Income group |  | 3.670 | 0.540 | −0.451 | 0.907 |
Living habits | |||||
| Â | Smoking | 5.488 | 0.359 | 5.761 | 0.174 |
|  | Second-hand smoke exposure | −7.886 | 0.192 | −0.614 | 0.904 |
|  | Drinking | −3.206 | 0.592 | −2.738 | 0.679 |
| Â | Exercise | 3.532 | 0.551 | 7.535 | 0.227 |
Dietary habits | |||||
|  | Number of meals per day | −12.000 | 0.043 | −1.863 | 0.285 |
| Â | Eating breakfast | 3.619 | 0.541 | 3.001 | 0.325 |
|  | Eating meat | −7.673 | 0.176 | −2.575 | 0.157 |
| Â | Eating fresh vegetables | 4.146 | 0.515 | 2.924 | 0.317 |
|  | Eating fresh fruits | −17.973 | 0.001 | 0.000 | 1.000 |
|  | Eating pickles | −12.717 | 0.032 | 1.040 | 0.414 |
|  | Salt | −15.795 | 0.008 | −1.910 | 0.303 |
