Test-retest reliability, internal consistency, construct validity and factor structure of a falls risk perception questionnaire in older adults with type 2 diabetes mellitus: a prospective cohort study

BACKGROUND: Older adults with type 2 diabetes (DM2) are at increased risk of falling due to complications including: diabetic peripheral neuropathy, diabetic retinopathy, autonomic neuropathy and diabetic foot ulcers. The purpose of this study was to determine the test-retest reliability, internal consistency, construct validity and to perform factor analysis of a new falls Risk Perception Questionnaire (RPQ) in older community-dwelling adults with DM2. METHODS: A prospective cohort of 30 community-dwelling older adults, ≥ 55 years, with DM2 was assembled. At baseline, perceived risk of falling, fear of falling and physical activity were measured. At time 2 (T2), at least 2 days later, perceived risk of falling was assessed again to determine the test-retest reliability of the RPQ. At time 3 (T3), approximately six weeks later, and time 4 (T4), at least 2 days after T3, perceived risk of falling was assessed by phone to determine the test-retest reliability of the RPQ when administered by phone. RESULTS: The RPQ demonstrated excellent test-retest reliability when delivered in person (ICC = 0.78, 95% Confidence Interval, CI: 0.59–0.89) and by phone (ICC = 0.82, 95% CI: 0.65–0.91), good internal consistency (α = 0.78) and adequate construct validity (r = 0.52, 95% CI: 0.20–0.74, p = 0.003) in older adults with DM2. CONCLUSION: Given the good psychometric properties in this sample of persons with Diabetes, the RPQ has the potential to be used in clinical practice as a risk assessment and fall prevention tool. However, further testing needs to be done using a larger sample.