Clinicians use the Activities-specific Balance Confidence (ABC) Scale to understand balance confidence. A short-form ABC scale was also developed using the six most difficult tasks from the original scale. The short-form scale psychometrics and agreement with the original scale, however, have yet to be explored in people with lower-limb amputations.
A study published in September in the journal Prosthetics and Orthotics International, determined the relative and absolute reliability, construct validity, and agreement of the short-form ABC scale.
Analysis for relative reliability and internal consistency was intraclass correlation coefficient and Cronbach’s α, respectively. Absolute reliability was measured using standard error of measurement and minimal detectable change. Bland–Altman plots measured agreement between scales. Construct validity was evaluated against the L Test using a Pearson-product moment correlation.
The short-form ABC (intraclass correlation coefficient = 0.92) and ABC (intraclass correlation coefficient = 0.91) scales had excellent relative reliability, the study found. Both scales demonstrated good internal consistency. Worse absolute reliability was observed in the short-form ABC scale. Construct validity against the L Test was confirmed. Bland–Altman plots indicated poor agreement between scales.
Both scales exhibit excellent relative reliability and good internal consistency and construct validity. Researchers found that poor agreement between short-form ABC and ABC indicates the scales should not be used interchangeably. Inadequate absolute reliability of the short-form ABC scale suggests the ABC should be the balance confidence scale of choice.
Researchers determined that balance confidence is an important metric toward the understanding of rehabilitation and community re-integration in people with lower-limb amputations. Due to inferior absolute reliability and a lack of appropriate items composing the short-form ABC scale, the full-scale ABC is recommended for the assessment of balance confidence in this population.