“The L test under single and dual-task conditions in women with fibromyalgia: A psychometric study”

Introduction This study aimed to investigate the test-retest reliability of the L test under single and dual-task conditions in women with fibromyalgia. To analyze the concurrent validity of the L test and Timed Up and Go test (TUG) and the relationship between the L test and the impact of the disease. Methods A cross-sectional study with 22 women with fibromyalgia. The Intraclass Correlation Coefficient (ICC) 3,1 evaluated the reliability. The concurrent validity was established between the L test and the TUG. The Pearson product-moment correlation assessed the correlation between the L test and the impact of the disease. Results Results revealed an ICC of 0.95 (0.876–0.979) in the single condition with the stopwatch and 0.95 (0.872–0.978) with the Chronopic. In the dual-task condition 0.93 (0.832–0.971) with the stopwatch and 0.94 (0.854–0.975) with the Chronopic.The L test and the TUG showed significant relationships with a stopwatch in the single (test-r = 0.839; retest-r = 0.897) and the dual-task conditions (test-r = 0.793; retest-r = 0.882). These findings were also found with the Chronopic in the single (test-r = 0.876; retest-r = 0.901) and the dual-task conditions (test-r = 0.872; retest-r = 0.897).Significant relationships were found between the L test and the impact of the disease with a stopwatch in the single (test-r = 0.502; retest-r = 0.647) and the dual-task conditions (test-r = 0.428; retest-r = 0.571). And with the Chronopic in the single (test-r = 0.528; retest-r = 0.663) and the dual-task conditions (test-r = 0.482; retest-r = 0.608). Conclusions L test is a reliable tool under single and dual-task conditions in women with fibromyalgia. This test is a valid method when compared with the TUG, and it is related to the impact of the disease.