Smartphone-Based Measurement of Cognition and Physical Function in Older Emergency Department Patients: A Feasibility Study.

BACKGROUND: Falls are a leading cause of emergency department (ED) visits among older adults and represent a critical opportunity to identify cognitive and functional impairments that influence treatment and recovery. While smartphone- and wearable-based assessments are increasingly used to assess cognitive and physical function in older adults, their feasibility in the ED setting, particularly after a fall, remains unclear. METHODS: From August 2021 to January 2024, community-dwelling older ED patients (≥ 65 years) were screened for cognitive impairment (six-item screener) and functional limitations (modified Barthel Index, mobility equipment). Apple ResearchKit digital assessments measured cognition (Stroop, Trail Making, reaction time) and physical function (gait/balance, timed walk). Wearable devices monitored movement. Feasibility was examined via attempt and completion rates. Reasons for non-attempt/non-completion and associations with patient characteristics were explored. RESULTS: Among 196 patients (mean age 78.2 ± 7.6 years, 68% women), 77% attempted at least one digital assessment. Cognitive tests had moderate-to-high completion rates (68%-87%) among those who attempted, and completion was associated with lack of cognitive impairment (p = 0.002, 0.002, 0.01, for Stroop, Trail Making, and reaction time tests, respectively). Non-completion was due most often to lack of glasses, not feeling well, or technology issues. Physical function tests had much lower completion rates (18%-20%), and completion was associated with functional status (Barthel Index; p = 0.02, 0.01 for gait and balance and timed walk tests) and mobility equipment use (p = 0.02, 0.03). Low completion rates were mainly due to safety concerns, pain, and injury. CONCLUSIONS: Digital assessment of cognitive function is feasible in most older adults presenting to the ED for falls, but physical function tests had low feasibility in this population. Future research will explore whether such data predict clinically relevant outcomes (e.g., time to injury recovery, ED revisits) and can inform personalized intervention (e.g., physical therapy referrals, skilled nursing facility placement). TRIAL REGISTRATION: Clinical Trial Number: NCT04304495.