Reliability, minimum detectable change, and minimum clinically important difference of the balance subtest of the Bruininks-Oseretsky test of motor proficiency-second edition in children with cerebral palsy.

Purpose: This study aimed to investigate the internal consistency, inter-rater, and test-retest reliability of the balance subtest of the Bruininks-Oseretsky test of motor proficiency-second edition (BOT-2) and to estimate the minimum detectable change (MDC) and minimum clinically important difference (MCID) of the balance subtest of the BOT-2 in children with cerebral palsy (CP).

Methods: In total, 20 children with CP participated in the present study. Internal consistency, test-retest, and inter-rater reliability were computed to establish reliability of the balance subtest of the BOT-2. The MDC95 was estimated from the standard error of measurement (SEM) to determine a real change for an individual child with CP. The anchor- and distribution-based MCID were calculated to determine the smallest change that might be important to clinicians. For concurrent validity, the correlation between the balance subtest of the BOT-2 and the pediatric balance scale (PBS) were calculated using Spearman's correlation.

Results: Internal consistency was good (Cronbach's alpha coefficient = 0.89). The BOT-2 had excellent test-retest (ICC = 0.99, p < 0.001) and inter-rater reliability (ICC = 0.99, p < 0.001). The balance subtest of the BOT-2 had an SEM of 0.70, MDC95 of 9.61, and MCIDs of 2.54 (anchor-based) and 1.38 (distribution-based). Additionally, there was a moderate positive correlation between the balance subtest of the BOT-2 and the PBS (Spearman's rho = 0.629, p = 0.003).

Conclusions: Our experimental results indicate that the balance subtest of the BOT-2 had good internal consistency, along with excellent test-retest and inter-rater reliability. The change in scores of an individual child with CP should attain 9.61 points on the balance subtest of the BOT-2 to indicate a clinically important change. The MDC95 and MCID values could be helpful in understanding therapeutic effects and evaluating balancing ability using the balance subtest of the BOT-2 in children with CP.