Intra-rater and inter-rater reliability of the Penn Spasm Frequency Scale in People with chronic traumatic spinal cord injury. Issue 6 (June 2018) - Mills, Patricia
Abstract Study design Psychometric study. Objectives Evaluate the intra-rater and inter-rater reliability of the Penn Spasm Frequency Scale (PSFS) in people with chronic traumatic spinal cord injury (SCI). Setting Community setting. Methods Participants with chronic traumatic SCI were administered the PSFS, a self-reported spasticity measure in which the individual documents the frequency (Part 1) and severity (Part 2) of their muscle spasms. One rater administered the PSFS at baseline, 5 to 10 days, and 4 to 6 weeks after baseline. The second rater administered the PSFS within 3 days of the first rater. Results Reliability was assessed using weighted-kappa (95% confidence interval) statistics. In 61 participants, the intra-rater reliability between 5 to 10 days and 4 to 6 weeks after baseline was 0.822 (0.709, 0.935) and 0.734 (0.586, 0.883), respectively, for PSFS Part 1. With the addition of Part 2, the intra-rater reliabilities were 0.812 (0.705, 0.919) and 0.729 (0.586, 0.872) for 5 to 10 days and 4 to 6 weeks, respectively. The PSFS inter-rater reliability within a 3-day time interval was 0.862 (0.759, 0.965) for Part 1 and 0.857 (0.762, 0.952) with the addition of Part 2. Conclusions PSFS Part 1 intra-rater and inter-rater reliability weighted-kappa statistics are in the "almost perfect" category, with lower confidence bounds in the "substantial" range. By adding Part 2 the reliability decreases, but the kappa statistics remain "substantial, " with a lower confidence bound in the "moderate" range. The PSFS is probably a reliable outcome measure to assess self-reported spasticity after chronic traumatic SCI.