Test-retest reliability of four sensory measures in people with multiple sclerosis.

Abstract

This study investigated the test-retest reliability of the Neurothesiometer (NT), Verbal Analogue Scale for sensation (VAS), Erasmus modifications to the Nottingham Sensory assessment (EmNSA) and Semmes-Weinstein monofilaments (SWM) in people with multiple sclerosis (MS). A random sample of 34 people with MS who walked with or without an assistive device participated in this study. Participants were tested twice with the NT, VAS, EmNSA and SWM, 1 week apart. For categorical data, Cohen's kappa (Κ), percentage agreement (P0) and prevalence-adjusted bias-adjusted kappa (PABAK) were used. For continuous data, intraclass correlation coefficients [ICC (3,1)] with 95% confidence intervals (95% CI), Bland-Altman plots and standard error of measurement (SEM) were calculated. The ICC values for NT were good, being the highest for the plantar aspect of the heel (ICC=0.92, 95% CI 0.85-0.96, SEM=4.24). Good ICC values were obtained for VAS questions on numbness, pins and needles and temperature and were supported by low SEM. Κ values for SWM were poor, ranging from 0.11 to 0.46 for the upper limb and 0.12 to 0.29 for the lower limb. Findings for EmNSA need further verification because of a possible ceiling effect in this test. The NT and VAS assessments for sensation had good test-retest reliability and should be considered for measuring changes in sensation in ambulatory people with MS. In contrast, findings from EmNSA and SWM revealed either questionable or poor test-retest reliability, suggesting that these two measures need further investigation.