Validity and reliability of assessing strength and balance improvements by videoconference in pre-frail and frail older adults

BACKGROUND: Assessing older adults' physical function via videoconferencing technology is acceptable and feasible, enabling researchers and practitioners to monitor mobility remotely. However, validity of remote assessment in pre-frail and frail older adults, and its ability to detect change with intervention, has yet to be established.

AIM: To establish the validity of remote physical function assessment in pre-frail and frail older adults compared to in-person assessment, and its reliability in detecting improvements in physical function during a 12-week exercise training intervention.

METHODS: Participants aged ≥ 65 years identified as pre-frail or frail based on in-person Short Physical Performance Battery scores ≤ 8 completed remote and in-person assessment of the 5x sit-to-stand, 60-second sit-to-stand, and single leg standing balance four times over 12-weeks (n = 49 at baseline, 40 at follow-up), with one group improving physical function with homebased exercise. Intraclass Correlation Coefficient and Bland Altman plots were used to determine agreement between assessment settings and consistency across the range of observed scores respectively in both Exercise and Control groups over time.

RESULTS: Remote assessment of sit-to-stand tests had good-to-excellent agreement with in-person assessment, and balance tests had moderate-to-good agreement. In the Exercise group, absolute bias in sit-to-stand tests was observed in both remote and in-person assessments at 4, 8, and 12 weeks, though this was not statistically different to the Control group.

DISCUSSION: Remotely assessing physical function in pre-frail and frail older adults is promising when compared to in-person assessments; however, there may be a bias towards better test performance over time when assessed remotely compared to in-person.

CONCLUSIONS: Monitoring change in physical function in pre-frail and frail older adults using remote assessment is useful but should consider potential bias in measurement outcomes. Larger and more specific studies are needed to conclusively demonstrate the validity of remote assessment compared to in-person assessment when dealing with pre-frail and frail older people.