Reliability and Validity of the Composite Activity-Related Fall Risk Scale

Abstract

IntroductionThe newly developed Composite Activity-related Risk of Falls Scale (CARFS) is designed to measure composite activity-related risk of falls (CARF) in relation to the activity-specific fear of falling and physical behavior. This study tested the reliability and validity of the CARFS in older people with various health statuses and persons with stroke or spinal cord injury.MethodsParticipants included 70 older adults, 38 persons with stroke, and 18 with spinal cord injury. They were first surveyed using a combined questionnaire including the CARFS and activity-specific balance confidence (ABC) scale in addition to items asking for personal and disease-related information, fall history, walking independence levels for examining internal consistency, ceiling and floor effects, and convergent validity in each participant group. One week after the initial survey, 33 older participants were reexamined using the CARFS to analyze test-retest reliability, where a minimal detectable change was found. Significance was set at α = 0.05 for all analyses.ResultsThe CARFS showed excellent test-retest reliability in the dimensions of fear of falling, physical behavior, and CARF [ICC (3,1) = 0.972, 0.994, and 0.994, respectively for their overall score], with a minimal detectable change of 3.944 in the older population. The internal consistency of CARFS items was excellent in the older participants, good in participants with stroke or spinal cord injury (Cronbach's alpha = 0.945, 0.843, 0.831 in each participant group, respectively). No ceiling and floor effects were demonstrated in the wide range of people. For the convergent validity, overall CARF score was significantly correlated with the average ABC score in each participant group (rho = −0.824, −0.761, and −0.601, respectively; p < 0.01), and was significantly correlated with walking independence levels in each participant group (rho = −0.636, −0.423, and −0.522, respectively; p < 0.01). It showed weak correlation with the number of previous falls only in participants with stroke (rho = 0.291, p = 0.076).ConclusionThe CARFS is a reliable and valid tool for measuring fall risk in older people and persons with stroke or spinal cord injury.

Daily Activity Restriction Quantification in Older Population via Using Activity Frequency: Dual Roles in Preventing Falls

“…For daily activity restriction, we are the first to propose a quantification method based on activity frequency [5][6][7]. We designed a question, "How often have you performed the following activities in the previous 1-month period?"…”

“…We are the first to evaluate the impact of activity restriction on the risk of falls by quantifying activity restriction, fear of falling, and their interaction [6,7]. Based on it, a tool to evaluate the risk of falls in older people and persons with physical disabilities has been developed: the Composite Activity-specific Risk of Falls Scale (CARFS).…”

“…The question on fear of falling is "How much fear of falling do you have when you perform the following activities, " with the answer scored by a 5-point Likert scale (fear of falling: 0, no worry; 1, slight worry; 2, moderate worry; 3, high worry; and 4, extreme worry). The composite risk of falls for each item (C) was estimated by the degree of fear of falling (A) and activity frequency (B) using the formula C = A+(4-B)+A´B/2, where 4-B indicates the degree of activity restriction [6,7]. The notion underlying the formula is that daily activity restriction is beneficial when the fear of falling is high (possibly due to dangerous environmental hazards or poor physical ability) but unnecessary and even harmful when the fear is mild or nonexistent.…”

“…The CARFS is promising for screening fall risk and modifying physical behavior to prevent falls. It is a reliable and valid tool for measuring the risk of falls, demonstrating excellent testretest reliability, excellent internal consistency of the CARFS items, good-to-excellent convergent validity with the ABC scale and ambulation, and no ceiling or floor effects in older patients and patients with physical disabilities due to stroke or spinal cord injury [7]. However, evidence on the predictive validity of falls, sensitivity to change, and effectiveness of optimizing physical behavior for fall prevention have yet to be established in the target population.…”