Table 2.
Multiple regression parameter tests.
| Factor | F | d.f. | P |
|---|---|---|---|
| Age | 966.16 | 2 | <.0001 |
| Nonlinear | 1.71 | 1 | 0.1915 |
| Study | 43.91 | 7 | <.0001 |
| Race (Factor + Higher Order Factors) | 58.56 | 16 | <.0001 |
| All Race Interactions | 3.15 | 14 | 0.0001 |
| Gender (Factor + Higher Order Factors) | 20.85 | 12 | <.0001 |
| All Gender Interactions | 7.01 | 11 | <.0001 |
| Education (Factor + Higher Order Factors) | 20.80 | 6 | <.0001 |
| All Education Interactions | 5.76 | 5 | <.0001 |
| Income (Factor + Higher Order Factors) | 9.27 | 12 | <.0001 |
| All Income Interactions | 2.99 | 10 | 0.0009 |
| Nonlinear (Factor + Higher Order Factors) | 3.30 | 6 | 0.0030 |
| Race * Education (Factor + Higher Order Factors) | 2.00 | 4 | 0.0919 |
| Gender * Education (Factor + Higher Order Factors) | 7.07 | 3 | 0.0001 |
| Race * Gender (Factor + Higher Order Factors) | 3.53 | 8 | 0.0004 |
| Race * Income (Factor + Higher Order Factors) | 3.13 | 8 | 0.0015 |
| Nonlinear (Factor + Higher Order Factors) | 3.89 | 4 | 0.0037 |
| Nonlinear Interaction: f(A,B) vs. AB | 4.08 | 2 | 0.0170 |
| Gender * Income (Factor + Higher Order Factors) | 3.34 | 6 | 0.0027 |
| Nonlinear (Factor + Higher Order Factors) | 4.07 | 3 | 0.0067 |
| Nonlinear Interaction: f(A,B) vs. AB | 11.89 | 1 | 0.0006 |
| Race * Gender * Education (Factor + Higher Order Factors) | 1.05 | 2 | 0.3512 |
| Race * Gender * Income (Factor + Higher Order Factors) | 3.37 | 4 | 0.0091 |
| Nonlinear | 3.89 | 2 | 0.0204 |
| TOTAL NONLINEAR | 3.08 | 7 | 0.0030 |
| TOTAL INTERACTION | 5.37 | 17 | <.0001 |
| TOTAL NONLINEAR + INTERACTION |
5.12 |
19 |
<.0001 |
| TOTAL | 213.70 | 32 | <.0001 |
Tests for Race, Gender, Education, and Income consider all terms in which those variables are included. For example, the pooled 16 d.f. test of Race includes the main effect of Race, 2-way interactions with Gender, non-linear Income, and Education, and three-way interactions with Gender and non-linear Income, and Gender and Education. Tests of nonlinearity are based on restricted cubic spline with 3 knots. Similarly, the pooled test of, say, Race by Income, consider that 2-way interaction, plus the 3-way Race by Gender by Income interaction.