Table 4.
Cox proportional hazards hierarchical regression model evaluating the influence of vitamin D levels and depression on survival
| Model 0 | Survival | CI | |||
|---|---|---|---|---|---|
| Regression coefficient | HR | P value | Lower | Upper | |
| Age | 0.00 (0.01) | 1.002 | 0.87 | 0.975 | 1.031 |
| Sex | −0.16 (0.29) | 0.855 | 0.59 | 0.481 | 1.521 |
| BMI | −0.05 (0.03) | 0.949 | 0.09 | 0.894 | 1.008 |
| χ2 change 3.121, p=0.37 | |||||
| Model 1 | Survival | CI | |||
| Regression coefficient | HR | P value | Lower | Upper | |
| Age | 0.01 (0.01) | 1.009 | 0.54 | 0.981 | 1.037 |
| Sex | −0.21 (0.30) | 0.811 | 0.48 | 0.453 | 1.452 |
| BMI | −0.06 (0.03) | 0.942 | 0.05 | 0.886 | 1.001 |
| Vitamin D (log) | −1.96 (0.76) | 0.141 | 0.01 | 0.030 | 0.655 |
| χ2 change 6.228, p=0.01 | |||||
| Model 2 | Survival | CI | |||
| Regression coefficient | HR | P value | Lower | Upper | |
| Age | 0.01 (0.01) | 1.007 | 0.64 | 0.979 | 1.036 |
| Sex | −0.22 (0.30) | 0.807 | 0.47 | 0.45 | 1.444 |
| BMI | −0.06 (0.03) | 0.939 | 0.04 | 0.883 | 0.998 |
| Vitamin D (log) | −1.77 (0.82) | 0.171 | 0.03 | 0.034 | 0.851 |
| Depression | 0.03 (0.03) | 1.029 | 0.30 | 0.975 | 1.085 |
| χ2 change 1.018, p=0.31 | |||||
| Model 3 | Survival | CI | |||
| Regression coefficient | HR | P value | Lower | Upper | |
| Age | 0.01 (0.01) | 1.006 | 0.69 | 0.978 | 1.034 |
| Sex | −0.22 (0.29) | 0.803 | 0.46 | 0.451 | 1.430 |
| BMI | −0.06 (0.03) | 0.941 | 0.04 | 0.887 | 0.998 |
| Vitamin D (log) | −3.99 (1.41) | 0.018 | 0.005 | 0.001 | 0.294 |
| Depression | −0.56 (0.30) | 0.570 | 0.06 | 0.318 | 1.025 |
| Vitamin D × depression | 0.42 (0.21) | 1.522 | 0.04 | 1.009 | 2.296 |
χ2 change 4.284, p=0.04.
BMI, body mass index.