Table 3.
Estimates from the population-averaged GEE model investigating associations with vitamin D level
| Parameter | Estimate | Standard error | P-value | Overall p-value |
|---|---|---|---|---|
|
Intercept |
64.5883 |
2.4201 |
<.0001 |
<.0001 |
|
Age (years) |
|
|
|
<.0001 |
| age_RCS_lin |
−0.2738 |
0.0422 |
<.0001 |
|
| age_RCS_S1 |
0.0015 |
0.0001 |
<.0001 |
|
| age_RCS_S2 |
−0.0030 |
0.0004 |
<.0001 |
|
| age_RCS_S3 |
0.0008 |
0.0004 |
0.0823 |
|
|
Median household income ($CDN 10000) |
|
|
|
<.0001 |
| income_RCS_lin |
−0.4078 |
0.2350 |
0.0826 |
|
| income_RCS_S1 |
0.0543 |
0.0263 |
0.0392 |
|
| income_RCS_S2 |
−0.1270 |
0.0793 |
0.1092 |
|
| income_RCS_S3 |
0.0824 |
0.0855 |
0.3352 |
|
|
Percentage of immigrants |
|
|
|
<.0001 |
| percentimmi__RCS_lin |
−7.6190 |
9.4844 |
0.4218 |
|
| percentimmi__RCS_S1 |
−172.823 |
567.4589 |
0.7607 |
|
| percentimmi__RCS_S2 |
−1122.79 |
1547.330 |
0.4681 |
|
| percentimmi__RCS_S3 |
3152.879 |
1511.398 |
0.0370 |
|
|
Percentage of aboriginal people |
|
|
|
<.0001 |
| percentabor__RCS_lin |
−68.5534 |
15.3580 |
<.0001 |
|
| percentabor__RCS_S1 |
13868.36 |
5311.648 |
0.0090 |
|
|
Percentage of subjects with some post-secondary education |
|
|
|
<.0001 |
| percentuniv_RCS_lin |
13.6596 |
4.2690 |
0.0014 |
|
| percentuniv_RCS_S1 |
237.8126 |
69.0070 |
0.0006 |
|
| percentuniv_RCS_S2 |
−842.990 |
263.7487 |
0.0014 |
|
| percentuniv_RCS_S3 |
1090.294 |
509.4453 |
0.0323 |
|
|
Gender |
|
|
|
<.0001 |
| Female |
7.4674 |
0.1930 |
<.0001 |
|
| Male |
0.0000 |
0.0000 |
. |
|
|
Month of vitamin D testing |
|
|
|
<.0001 |
| December |
−1.3870 |
0.5024 |
0.0058 |
|
| November |
0.1357 |
0.4583 |
0.7672 |
|
| October |
−1.3138 |
0.4593 |
0.0042 |
|
| September |
−0.1319 |
0.4590 |
0.7738 |
|
| August |
4.7383 |
0.4252 |
<.0001 |
|
| July |
3.7308 |
0.4142 |
<.0001 |
|
| June |
0.5034 |
0.3959 |
0.2035 |
|
| May |
3.5073 |
0.4330 |
<.0001 |
|
| April |
0.6403 |
0.4129 |
0.1209 |
|
| March |
−3.6969 |
0.4045 |
<.0001 |
|
| February |
0.4483 |
0.4108 |
0.2751 |
|
| January | 0.0000 | 0.0000 | . |
Note: Age, median household income, percentage of immigrants, and percentage of subjects with some post-secondary education were coded using restricted cubic spline (RCS) functions with five knots located at the 5th, 25th, 50th, 75th, and 95th percentiles of their distribution, and percentage of aboriginal people was coded using the 5th, 50th and 95th percentiles of its distribution. The variables listed underneath each of the continuous variables are their corresponding spline variables (e.g., age_RCS_lin, age_RCS_S1, age_RCS_S2, and age_RCS_S3 are the 4 spline variables of age).