Evidence of the psychometric qualities of a simplified version of the Activities-specific Balance Confidence scale for community-dwelling seniors

OBJECTIVE: To evaluate the validity, reliability, and item hierarchy of a modified version of the Activities-specific Balance Confidence (ABC) scale using an item-response theory framework and integrating modifications aimed at increasing user-friendliness and promoting better congruence of the scale with public health falls prevention strategies. DESIGN: Cross-sectional study. SETTING: Community-based. PARTICIPANTS: Two hundred community-dwelling seniors involved in an effectiveness study of a falls prevention program. Participants were recruited by community-based organizations. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Balance confidence. RESULTS: The modified ABC scale (called ABC-Simplified [ABC-S] scale) has high internal consistency (reliability index, .86) and good convergent validity (statistically significant associations with perceived balance; performances on the one-leg stance, tandem stance, tandem walking, functional reach, and lateral reach [on the right side] tests; fear of falling; and occurrence of falls in the previous 12 mo). Analyses also showed differing degrees of difficulty across items, allowing for a determination of the scale's item hierarchy. CONCLUSIONS: The ABC-S scale is a valid and reliable measure for the assessment of balance confidence among community-dwelling seniors. The fact that this measure was validated with high-functioning seniors makes it particularly well-suited for identifying community-dwelling seniors who are beginning to lose confidence in their balance and who could benefit from community falls prevention programs.