Good correlation found
To determine the correlation and the test-retest reliability of the data obtained during the repeated home tasks, Mr. Rose and collaborators used Pearson’s correlation R2 and the intra-class correlation coefficients (ICC).
ICCs for various gait and chair stand variables obtained with the sensors were between 0.85 and 0.96 for the test-retest reliability during the remote home visit, and R2 ranged between 0.81 and 0.95. Variables include stance, cadence (steps per minute), step duration and length, speed, and chair stand duration.
With regard to the agreement between the home versus lab results, ICCs ranged between 0.63 and 0.9.
“There were some logistical and technological challenges with the approach,” Mr. Rose conceded. “Despite written and verbal instructions, 2 of the 20 participants ended up having gait data that was unusable in the home visit.”
Another limitation is that the study population, while “representative,” contained a higher number of individuals than the general population who identified as being White (95%) and female (85%), and 90% had a college degree.
“Individuals typically representative of an OA population were generally accepting and willing to participate in remote visits showing the feasibility of our approach,” Mr. Rose said.
“We need to determine the responsiveness of gait and chair stand outcomes from wearable sensors at home to change over time.”
The study was sponsored by Boston University with funding from Pfizer and Eli Lilly. The researchers used the OPAL inertial sensor (APDM Wearable Technologies) in the study. Mr. Rose made no personal disclosures. Four of his collaborators were employees of Pfizer and one is an employee of Eli Lilly & Company, all with stock or stock options.