Regression Models of Association Between Performance-Based Function and Self-Reported Disability The correlation between the WHODAS and SPPB total scores was considered strong (r=.65). When plotting SPPB scores against WHODAS scores (Figure), the data indicated that the variability in WHODAS scores was higher for participants with lower SPPB scores, suggesting that the association between WHODAS and SPPB scores is weaker for people with lower levels of performance. The total SPPB score explained 41.7% of the variance in WHODAS 2.0 scores (R2=41.7%, adjusted f?2=4l.6%).
Correlation coefficients between the SPPB subtest scores and WHODAS total
score ranged from -.51 (gait subtest) to — .55 (for both sit-to-stand and balance subtests). Entering the individual scores of each of the 3 subtests, the multivariate model explained a similar proportion of the variance in WHODAS 2.0 scores (R2=44.6%, adjusted /?2=44.0%) (Tab. 4) as for the total SPPB score (see previous paragraph).
Table 5 presents results for regression analysis for total WHODAS scores when other variables were included in the model. Only the SPPB subtest scores, GDS score, number of pain sites, pain intensity, and RAPA score were considered predictors of the WHODAS 2.0 scores in the model. Together, these predictors explained 60.5% of the variance in WHODAS scores. The variables of age,