Assessment of Internal Consistency and Convergent Validity of the Activities-specific Balance Confidence (ABC) Scale Thai Version

Abstract

Abstract Objective: To assess the internal consistency of the Activities-specific Balance Confidence (ABC) Scale Thai version and convergent validity of the scale compared with the Fall Efficacy Scale (FES) Thai version and Timed Up and Go Test (TUG). Method: The internal consistency, convergent validity and floor/ceiling effects of the ABC scale were assessed in 40 healthy older Thai adults with the mean age of 66.5 ± 5.7 years. The internal consistency was determined using the Cronbach’s alpha coefficient, item total correlation and Cronbach’s alpha coefficient if items deleted. The convergent validity of the ABC scale Thai version was assessed using the FES scale Thai version and TUG. Correlations between the scales were determined by the Spearman’s rank correlation, whereas the floor/ceiling effects were confirmed by the skewness analysis. Results: The internal consistency of total ABC scores was high (Cronbach’s alpha coefficient = 0.96). There was a significant correlation between the ABC scale Thai version and the TUG, albeit low degree of correlation (Spearman’s rho = -0.34), and another significant correlation with the FES scale Thai version (Spearman’s rho = 0.66) was identified. There was no significant floor effect in the ABC scale Thai version and the FES scale Thai version, but the ceiling effect was found only in the FES scale Thai version (-1.27). The proportion of those persons with full scores of the ABC scale was significantly lower than those of FES scale (7.50% vs. 42.50%, P < 0.05). Conclusion: the ABC scale Thai version had the high level of internal consistency reliability and moderate level of convergent validity with the FES scale Thai version. As the scale had no ceiling or floor effect, it is more sensitive than the FES scale when using in the highly functional older Thai persons. Keywords: internal consistency, convergent validity, Activities-specific Balance Confidence Scale Thai version, older Thai adults