Test-retest reliability and minimal detectable change of the SmartWheel clinical protocol.

Abstract

(1) To quantify the intra- and intersession reliability and minimal detectable change (MDC) of the SmartWheel clinical protocol (SCP) and (2) to compare the reliability of the SCP between experienced and naïve wheelchair users. Test-retest study. Biomechanics laboratory. Manual wheelchair users (WCUs) (n=10) with 1 to 32 years of wheeling experience and able-bodied (AB) naïve users (n=15). Not applicable. Wheelchair propulsion parameters including average peak force, push frequency, push length, and velocity were measured according to the SCP but with 5 trials per session, for 2 sessions. WCUs and AB users were analyzed separately. Intraclass correlation coefficients ([ICC](2,1) and ICC(2,5)) were calculated to assess intrasession reliability. ICC(2,1) and MDC (with 95% confidence) were calculated for each SCP parameter using a single trial from each session and with the mean of 5 repeated measures to evaluate intersession reliability. Intra- and intersession reliability for WCU parameters ranged from high to very high correlation (ICC range, .70-.99). For AB parameters, intrasession ICC(2,1) ranged from moderate to very high (ICC range, .50-.92), while intersession ICC(2,1) indicated low to very high correlation (ICC range, .25-.90). Estimates of standard error of measurement and MDC were provided for each parameter. For both WCUs and AB users, using the means from 5 trials increased intra- and intersession ICC and decreased MDC values. All MDC values were lower for WCUs compared with AB users. The SCP is a reliable method for assessing propulsion parameters in WCUs, even if just 1 trial is taken per session. AB users showed lower intra- and intersession reliability compared with WCUs. Therefore, for AB users or individuals with minimal wheeling experience, averaging multiple trials is recommended for the SCP.