The 16-question Activities-Specific Balance Confidence scale (ABC-16) and its shorter 6-question version, ABC-6, have good internal consistency reliability and moderate convergent validity in predicting balance confidence in people with multiple sclerosis (MS), a recent study found. However, poor sensitivity of both versions in distinguishing between MS groups at risk for falls may call into question the usefulness of this self-report. A total of 221 participants were included in this secondary analysis to compare the ABC-6 to the ABC-16. Convergent validity and internal consistency reliability were applied to participants based on their fall history and physiological fall risk. Researchers found:

• Statistical analysis indicated a main effect of group of the ABC-6 and the ABC-16.
• Both scales showed good to very good internal consistency with Cronbach's alphas ranging from 0.831 to 0.975 and good reliability with ICC scores ranging from 0.888 to 0.941.
• Furthermore, both versions had moderate convergent validity.
• Sensitivity ranged from 30% to 97% and specificity ranged from 64% to 100% across groups tested.