Table 4.
Regression Coefficients (Fixed Effects), Random Effects, and P-values From Multivariate HLM Models That Include Neighborhood SES in Addition to Individual Characteristics As Explanatory Variables For Fruit/Vegetable Intake, Using the Third National Health and Nutrition Examination Survey 1988-1994 (NHANES III) 1
| Servings of Fruit and Vegetables Combined (n=13,281) | Servings of Fruit (n=13,310) | Servings of Vegetables (n=13,296) | ||||
|---|---|---|---|---|---|---|
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| Coeff | P-value | Coeff | P-value | Coeff | P-value | |
| Neighborhood SES | 0.24 | <0.0001 | 0.13 | <0.0001 | 0.11 | 0.0006 |
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| Race/Ethnicity | ||||||
| Mexican American | 0.11 | 0.4986 | 0.21 | 0.0578 | -0.12 | 0.2951 |
| NH Black | -0.24 | 0.0509 | 0.16 | 0.0245 | -0.41 | <0.0001 |
| ‘Other’ | -0.24 | 0.2870 | -0.19 | 0.2398 | -0.04 | 0.7659 |
| NH White (ref) | --- | --- | --- | --- | --- | --- |
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| Age (centered) | 0.02 | <0.0001 | 0.02 | <0.0001 | 0.01 | 0.0146 |
| Age (centered) squared | -0.0001 | 0.3277 | 0.0001 | 0.1146 | -0.0003 | 0.0081 |
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| Female | -0.71 | <0.0001 | -0.09 | 0.0945 | -0.62 | <0.0001 |
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| US-born | -0.83 | <0.0001 | -0.62 | <0.0001 | -0.21 | 0.0757 |
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| Educational Attainment | ||||||
| Grade School | -1.14 | <0.0001 | -0.66 | <0.0001 | -0.48 | 0.0002 |
| Some High School | -0.77 | <0.0001 | -0.53 | <0.0001 | -0.25 | 0.0423 |
| High School | -0.46 | <0.0001 | -0.39 | <0.0001 | -0.07 | 0.4194 |
| Post High School (ref) | --- | --- | --- | --- | --- | --- |
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| Family Income | ||||||
| Poor | -0.52 | 0.0074 | -0.21 | 0.1103 | -0.30 | 0.0228 |
| Low income | -0.34 | 0.0468 | -0.14 | 0.1432 | -0.20 | 0.1201 |
| Middle income | -0.27 | 0.0341 | -0.07 | 0.4318 | -0.20 | 0.0314 |
| High income (ref) | --- | --- | --- | --- | --- | --- |
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| Employment status | ||||||
| Employed | 0.23 | 0.2277 | 0.06 | 0.5065 | 0.17 | 0.2907 |
| Not in Labor Force | 0.27 | 0.1346 | 0.09 | 0.2414 | 0.19 | 0.2600 |
| Unemployed (ref) | --- | --- | --- | --- | --- | --- |
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| Region | ||||||
| Northeast | 0.14 | 0.4948 | 0.07 | 0.5734 | 0.07 | 0.6037 |
| Midwest | 0.02 | 0.9021 | 0.04 | 0.7179 | -0.01 | 0.9477 |
| South | -0.27 | 0.1327 | -0.26 | 0.0103 | -0.01 | 0.9448 |
| West (ref) | --- | --- | --- | --- | --- | --- |
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| Intercept | 6.37 | <0.0001 | 2.39 | <0.0001 | 3.97 | <0.0001 |
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| Random Effects | ||||||
| Level 1 variance | 9.62 | <0.0001 | 3.32 | <0.0001 | 5.58 | <0.0001 |
| Level 2 variance | 1.97 | <0.0001 | 0.55 | <0.0001 | 1.09 | <0.0001 |
| Level 3 variance | 0.07 | 0.0490 | 0.04 | 0.0053 | 0.03 | 0.0717 |
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| ICC-level 2 (%) 2 | 16.90 | 13.95 | 16.23 | |||
| ICC-level 3 (%) 2 | 0.58 | 1.14 | 0.44 | |||
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| Fit Statistics | ||||||
| -2 Res LL | 77876.0 | 63752.7 | 70682.3 | |||
| AIC | 77882.0 | 63758.7 | 70688.3 | |||
Hierarchical linear models (HLM), or multi-level regressions, were conducted with PROC MIXED using SAS version 9.1. Level 1=individual level, level 2= tract level within counties, and level 3=county level.
ICCs = intra-class correlation coefficients, which provide an estimate of the proportion of total variance in dietary outcome that occurs between geographic areas. Level 2 ICCs provide an estimate of the proportion of variance in dietary outcome that occurs between tracts within counties while level 3 ICCs provide an estimate of the proportion of variance in dietary outcome that occurs between counties.