VIQ tests adjusted for SES Factors | ||
---|---|---|
Hazard ratio | Excess risk Explained by SES indicators | |
Gallup-Thorndike, uncorrected | 1.49 (1.28 to 1.75) | 0.73 (−0.05 to 1.02) |
Gallup-Thorndike, DIF corrected | 1.39 (1.20 to 1.61) | 0.69 (−0.11 to 0.97) |
Similarities, uncorrected | 1.30 (0.94 to 1.79) | 0.76 (−5.37 to 6.51) |
Similarities, DIF corrected | 1.17 (0.83 to 1.64) | 0.79 (−6.2 to 9.73) |
VIQ=verbal IQ. The HR is the Relative Index of Inequalities, or ratio of risk for those at the bottom of each distribution (ie, worst scoring or most disadvantaged) compared to those at the top. Percent of RII explained=excess risk explained by adjustment factor, computed as (HRunadjusted−HRadjusted)/(HRunadjusted−1) with 95% CIs based on bootstrap percentiles over 1000 replicates of 1000 observations. Same n=9381 for Gallup Thorndike and 2444 for WAIS-R similarities test. Results from separate Cox proportional hazard models for each factor, with age as time scale, all adjusted for gender as time-varying covariate due to non-proportional hazard. Minority status is also time varying, with estimates presented at age 50 years. DIF, differential item functioning; SES, socioeconomic status.