Reliability of digitally instructed self-reported 30-second chair stand test for lower extremity function

Area of Science:

• Gerontology
• Rehabilitation Medicine
• Digital Health

Background:

• The 30-second Chair Stand Test (30s CST) is a key measure for lower extremity physical function.
• Integrating validated tests into digital eHealth programs enhances accessibility for patients with chronic conditions.

Purpose of the Study:

• To evaluate the inter-rater reliability between digital self-assessment and in-person physiotherapist assessment of the 30s CST.
• To assess the intra-rater test-retest reliability of the digital self-assessment of the 30s CST.
• To determine the agreement of digital self-assessment for lower extremity function in individuals with hip or knee osteoarthritis.

Main Methods:

• Participants with hip or knee osteoarthritis performed the 30s CST via digital self-assessment and in-person physiotherapist assessment.
• Inter-rater reliability was assessed by comparing digital self-assessment with a physiotherapist's assessment.
• Intra-rater reliability was evaluated by having participants repeat the digital self-assessment twice, 10-14 days apart.

Main Results:

• Digital self-assessment yielded 1.5 more repetitions on average compared to in-person assessment.
• Inter-rater reliability (ICC) was 0.87, indicating low to excellent agreement.
• Intra-rater reliability (ICC) was 0.88, demonstrating good to excellent test-retest consistency.

Conclusions:

• The 30s CST can be reliably measured through digital self-assessment.
• Digital self-assessment provides a valid method for evaluating lower extremity function in older adults with osteoarthritis.
• This supports the use of digital self-assessment within eHealth interventions for osteoarthritis management.