Table 4.
Multiple linear regression results of waterpipe nicotine dependence (dependent) and depressive symptoms (independent).
| Variables | Values | (1) | (2) | (3) |
|---|---|---|---|---|
| Depressive symptoms | 1.127∗ (0.548, 1.706) | 0.859∗ (0.454,1.263) | 0.618∗∗ (0.362, 0.873) | |
| WTP smoking status | Nonsmoker | −19.972∗∗ (−21.929, −18.016) | −10.544∗∗ (−14.116, −6.972) | |
| Dual user | 11.907∗∗ (6.668, 17.145) | 8.162 (−1.951, 18.275) | ||
| Sex | 5.301∗ (0.790, 9.812) | 2.077 (−2.155, 6.309) | ||
| Grade | 0.160 (−1.986, 2.306) | −0.179 (−1.396, 1.039) | ||
| Age | 0.281 (−1.727, 2.289) | 0.648 (−0.263,1.560) | ||
| Father's work | Blue collar | −0.153 (−13.668, 13.361) | 1.207 (−12.629, 15.043) | |
| White collar | 3.109 (−9.780, 15.998) | 3.938 (−7.688, 15.565) | ||
| Father's current employment | 2.151 (−1.352, 5.654) | 0.991 (−4.309, 6.291) | ||
| Mother's work | Blue collar | −5.784 (−12.495, 0.927) | 9.608 (−11.601, 30.816) | |
| White collar | −10.453∗ (−19.043, −1.863) | 6.312 (−19.880, 32.503) | ||
| Housewife | −10.329∗ (−17.816, −2.843) | 7.302 (−18.520, 33.125) | ||
| Mother's current employment | −2.927 (−7.792, 1.939) | −1.738 (−8.020, 4.544) | ||
| Family members in the household | 0.096∗ (0.036, 0.156) | −0.117 (−0.253, 0.019) | ||
| Mother's smoking status | Cigarettes | 0.328 (−3.016, 3.672) | ||
| WTP | −3.047 (−11.475, 5.381) | |||
| Dual user | −2.948 (−12.697, 6.801) | |||
| Father's smoking status | Cigarettes | −1.127 (−4.261, 2.006) | ||
| WTP | 0.253 (−4.952, 5.457) | |||
| Dual user | 2.216 (−6.946, 11.379) | |||
| Siblings' smoking status | Cigarettes | 1.125 (−1.952, 4.201) | ||
| WTP | 3.001∗ (1.184, 4.818) | |||
| Dual user | 2.588∗ (0.425, 4.752) | |||
| Friends' smoking status | Cigarettes | 0.204 (−7.339, 8.513) | ||
| WTP | 4.007 (−1.493, 9.507) | |||
| Dual user | 8.045∗∗ (5.053, 11.037) | |||
| WTP smoked per week | 1.634 (−0.564, 3.832) | |||
| Feels need to smoke WTP | 8.861∗ (3.849, 13.874) | |||
| Constant | 39.569∗∗ (33.015, 46.122) | 58.938∗∗ (44.137, 73.740) | 33.515 (−7.260, 74.289) |
Statistically significant ∗(p < 0.05)∗∗(p < 0.01). The table shows the point estimate, followed by the 95% confidence interval in brackets. WTP smoking status' reference value was WTP-only smoker, and the other categorical variables used the first value reported above as the reference value. The table shows the results of the regression of the dependent variable waterpipe nicotine dependence calculated from the Waterpipe Nicotine Dependence Scale. The independent variable was depressive symptoms calculated from the depressive symptoms scale. The model controlled for potential confounders: waterpipe smoking status (nonsmoker, waterpipe-only smoker, and dual user), sex, age, grade [9–12], father's and mother's work (deceased, blue collar, white collar, and housemaker) and current employment as a proxy for socioeconomic status with the number of family members in the household, status of smoking for the parents, siblings, and friends (nonsmoker, cigarettes smoker, waterpipe smoker, or dual user), number of waterpipes smoked per week, and feeling a need to smoke waterpipes. The first model represents the crude unadjusted coefficient. The second model adjusts for the sex, grade, age, socioeconomic status, and WTP smoking status. The third model adjusts for all potential confounders considered in our study. The models are adjusted for the clusters and weights generated from the study design.