Table 2:
The relation of FTND score to age estimated by FPs with powers of 0.5 and 1
| Variables | β | SE | t | P | 95%CI | |
|---|---|---|---|---|---|---|
| Age (yr) | ||||||
| 1 | 4.591 | 1.632 | 2.813 | 0.005 | 1.385 | 7.796 |
| 2 | −0.339 | 0.114 | −2.959 | 0.003 | −0.564 | −0.114 |
| Marital status | ||||||
| Unmarried | 0.090 | 1.146 | 0.079 | 0.937 | −2.160 | 2.341 |
| Others | −0.407 | 0.503 | −0.808 | 0.420 | −1.395 | 0.582 |
| Occupation | −0.427 | 0.258 | −1.652 | 0.099 | −0.934 | 0.081 |
| Education | ||||||
| Middle | −0.041 | 0.285 | −0.143 | 0.887 | −0.600 | 0.519 |
| High | 0.335 | 0.373 | 0.900 | 0.368 | −0.396 | 1.067 |
| Smoking duration | 0.665 | 0.249 | 2.674 | 0.008 | 0.177 | 1.154 |
| Age of smoking onset | −0.166 | 0.162 | −1.021 | 0.308 | −0.485 | 0.153 |
| Constant | −13.046 | 5.842 | −2.233 | 0.026 | −24.519 | −1.572 |
Notes: FTND: score for Fagerström Test of Nicotine Dependence; FPs: fractional polynomials regression; Education: middle = primary and middle school, high = high school or more.