Electronically self-assessed functional capacity and exercise testing: A comparison of the Duke Activity Status Index and Patient-Reported Outcomes Measurement Information System tools

Abstract

Purpose: Electronic screening tools, such as Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function Short-Form 12a (PF-SF12a), may aid in the assessment of functional capacity. However, PROMIS PF-SF12a has not been validated against exercise capacity, or compared with established questionnaires, including the Duke Activity Status Index (DASI). We compared the DASI and PROMIS PF-SF12a to the maximum metabolic equivalents (METs) achieved during exercise stress testing.

Methods: DASI and PROMIS PF-SF12a were electronically administered to 100 adult patients (median age 56years, 61% male) immediately before exercise stress testing. DASI-predicted METs and PROMIS T score were calculated. Correlations with exercise METs with and without age adjustment were examined. Linear regression lines were derived and adjusted r² statistic was calculated. We compared models with the Davidson-Mackinnon J test.

Results: The median (interquartile range) DASI-predicted METs, PROMIS Tscore, and exercise METs were 8.97 (7.61-9.89), 47.90 (43.33-52.40), and 10.10 (10.10-12.80), respectively. In unadjusted correlation analyses, PROMIS accounted for 26% of the variance in exercise METs compared with 38% with DASI. With age adjustment, the r²values increased to 0.36 (PROMIS) and 0.46 (DASI). In both unadjusted and age-adjusted analyses, inclusion of DASI improved prediction of exercise METs beyond PROMIS T score (P<.0001). In contrast, PROMIS T score did not improve exercise MET prediction compared with DASI alone (P>.10).

Conclusion: Among patients undergoing clinically indicated exercise stress testing, DASI outperformed PROMIS PF-SF12a as a predictor of exercise METs.