Table 2.
Estimated Effects of County-Level and Individual-Level Factors on Depression: Income Inequality Main Effects
| Model 1 | Model 2 | |||
|---|---|---|---|---|
| Fixed Effect | Coefficients | Standard Error | Coefficients | Standard Error |
| Intercept | 1.8748*** | 0.0855 | 1.6868*** | 0.0680 |
| County-Level Variables | ||||
| Gini | 2.6432*** | 0.8043 | 2.5941*** | 0.8094 |
| Mean income | 0.0021 | 0.0030 | 0.0021 | 0.0029 |
| Individual-Level Variables† | ||||
| Age | −0.0027 | 0.0046 | −0.0028 | 0.0045 |
| Female | 0.1523*** | 0.0535 | 0.1469*** | 0.0531 |
| Married | −0.3588*** | 0.0543 | −0.3509*** | 0.0553 |
| Education | −0.0606*** | 0.0071 | −0.0596*** | 0.0074 |
| Income: | ||||
| Groups -Middle | −0.0016 | 0.0722 | ||
| -High | −0.0739 | 0.0797 | ||
| Spline -1st tercile (Low) | −0.0138 | 0.0145 | ||
| -2nd tercile (Middle) | 0.0004 | 0.0067 | ||
| -3rd tercile (High) | 0.0003 | 0.0007 | ||
| Wealth: | ||||
| Groups -Middle | −0.1741*** | 0.0642 | ||
| -High | −0.2089*** | 0.0698 | ||
| Spline -1st tercile (Low) | −0.0039** | 0.0020 | ||
| -2nd tercile (Middle) | −0.0009 | 0.0007 | ||
| -3rd tercile (High) | −0.0001*** | 0.0000 | ||
| Race/ethnicity | ||||
| Black-non-Hispanic | −0.0999 | 0.1171 | −0.1108 | 0.0760 |
| Hispanic | 0.2984** | 0.0772 | 0.2882** | 0.1163 |
| ADL limitations | 0.3376*** | 0.0285 | 0.3375*** | 0.0285 |
| IADL limitations | 0.1944*** | 0.0318 | 0.1934*** | 0.0319 |
| Number of illnesses | 0.2383*** | 0.0161 | 0.2374*** | 0.0161 |
| Random Effect‡ | Variance component | χ2 (d.f.) | Variance component | χ2 (d.f.) |
| County mean depression | 0.0320*** | 439.21 (190) | 0.031047*** | 436.15(190) |
| Individual-level variance | 3.1107 | 3.1094 | ||
p≤0.01
p≤0.05
p≤0.10 (two-tailed tests)
Note: Models 1 and 2 are random intercept models estimated based on the restricted maximum likelihood method, using unweighted data. All the continuous variables were centered to facilitate the interpretation of the intercept. The intercept represents the level of depression when independent variables are constrained at the average value for continuous variables or at the reference category for categorical variables. Depression is measured by an eight-item abbreviated CES-D scale, which ranges from 0 (not depressed at all) to 8 (maximum level of depression). Robust or “Huber-corrected” standard errors are reported.
Reference categories are male (gender), not currently married (marital status), low (income groups), and low (wealth groups).
The variance component of the intercept (county mean depression) represents the county-level residual variance or county effects that are left unexplained by the model, and the variance component of individual-level effects represent the individual-level residual variance.