Harnessing Digital Health To Objectively Assess Motor Capacity In Patient With Chronic Obstructive Pulmonary Disease

Abstract

PURPOSE: Current motor-capacity assessment tools based on gait test is limited in patients with Chronic Obstructive Pulmonary Disease (COPD) because of the need to carry ventilator support, high fall risk, fatigue, and limited space to administer the test in busy settings. In this study, we proposed an alternative tool to determine motor capacity based on 20-seconds rapid repetitive elbow flexion-extension test, called frailty meter (FM) administrable during sitting. FM is based on a single wrist-sensor enables quantifying frailty phenotypes including slowness, weakness, exhaustion, and rigidity. METHODS: Thirty-nine COPD patients (age = 68 ± 8 years, BMI = 29 ± 6 kg/m2) and 49 age-matched controls (age = 70 ± 3 years, BMI = 29 ± 6 kg/m2) were recruited. In addition to FM test, conventional functional tests, including gait, balance, timed up & go, and 5-time sit to stance were performed. RESULTS: All participants achieved to complete FM test. While the feasibility for conventional tests ranged from 74% to 90%. When compared to the controls, COPD patients exhibited deteriorated motor capacity measured by conventional functional tests (Cohen’s d=0.60-1.52, p<0.050). The most sensitive phenotypes associated with COPD was found to be slowness characterized by flexion time (42% deterioration, d=1.46, p<0.001) and rigidity characterized by range of motion (14% deterioration, d=0.73, p=0.001). Significant correlations were found between FM metrics and conventional functional tests with the largest effect observed between slowness and 5-time sit to stance (r=0.51, p<0.001). CONCLUSION: This study demonstrated the feasibility of the FM test to quantify digital biomarkers associated with motor capacity in COPD patients. The proposed test could be served as an alternative to gait tests and thus may facilitate routine screening of motor-capacity in busy clinical settings. Future studies need to demonstrate sensitivity to change in response to intervention.