Background: Limited research assessed the validity of the Activities-specific Balance Confidence, ABC) Scale in individuals with chronic obstructive pulmonary disease, COPD) at risk of falls. We report on the scale's construct and criterion validity.
Methods: Construct validity was established by assessing known groups, convergent, and divergent validity. A receiver operating characteristic, (ROC) curve and logistic regression examined the criterion validity of the scale.
Results: In 223 individuals with COPD, the ABC Scale significantly, (p < 0.001) discriminated between groups, with lower scores for females [Mean difference (MD) = 10%], rollator use [MD = 13%], and fallers [MD = 12%], and had a strong association [r = 0.58, p < 0.001] with Berg Balance Scale. The scale distinguished fallers from non-fallers with a cutoff value of 58% [Area Under the Curve = 0.64, 95% CI = 0.57-0.72, p < 0.001] and significantly identified fall status [B, SE = -0.03, 0.01, p < 0.001] with an odds ratio of 0.97 [95%CI = 0.96-0.99]. The sensitivity, specificity, and test accuracy were: 61, 58, and 60%, respectively.
Conclusion: The ABC Scale showed evidence for known groups, convergent, and divergent validity and can assist in identifying fall status in individuals with COPD.
Keywords: ABC Scale; COPD; balance confidence; fall status; validity.