Activity Measure for Post-Acute Care, Computer Adapted Test versus "6-Clicks"; do they agree in individuals post-ischemic acute stroke?

Abstract

To examine agreement between the AM-PAC Computer Adaptive Test (CAT) and the "6-Clicks" short forms across the Basic Mobility (BM), Daily Activity (DA), and Applied Cognition (AC) domains in individuals with ischemic stroke during acute hospitalization. Secondary analysis of a larger prospective, longitudinal cohort study. Acute care hospital. Individuals; 18 years and older, had a National Institute of Health Stroke Scale score, and a "6-Clicks" and CAT within 24 hours of each other. NA MAIN OUTCOME MEASURES: Agreement was assessed in four ways; 1) intraclass correlations (ICC); 2) weighted Kappa statistics, quartiles; 3) equivalence using the minimal detectable difference (MDD) of the domains; 4) Bland Altman plots, and 5) we calibrated the "6-Clicks t-scores using identity linking with the CAT t-scores. 137 individuals; 59% male; median age 66 years. The "6-Clicks" and CAT scores had poor agreement according to the ICC (BM: 0.58, DA: 0.64, AC: 0.48). Weighted Kappa was 0.74 and 0.63 for BM and DA, indicating good agreement; kappa 0.53 for AC, indicating moderate agreement. Assessment of equivalence finds they are equivalent with the mean differences. Bland-Altman plot for BM and DA had a negative trend indicating that on average the "6-Clicks" had a systematic bias and overestimated compared to the CAT score and AC had a positive trend. We found poor to moderate agreement between the CAT and the "6-Clicks", for all three domains, and systematic bias at higher and lower scores in this cohort of individuals post-stroke.