The reliability, validity and responsiveness of the Restless Legs Syndrome Quality of Life questionnaire (RLSQoL) in a trial population

BACKGROUND: The aim of this study was to determine the reliability, validity and responsiveness of the Restless Legs Syndrome Quality of Life questionnaire (RLSQoL) in a clinical trial setting. METHODS: Two matching, placebo-controlled, multinational studies assessing the effectiveness and safety of ropinirole for treating moderate-to-severe Restless Legs Syndrome (RLS) formed the basis of this psychometric assessment. Validity and reliability were assessed using baseline data. Responsiveness was determined using longitudinal data collected at baseline and 12 weeks. RESULTS: A total of 547 subjects formed the baseline validation population; 519 were used for assessing responsiveness (n = 284/263 and 271/248 for both studies, respectively). Construct validity assessment confirmed that an overall life impact score could be calculated. All item-scale correlations were = 0.4, except items 1 (r = 0.36) and 5 (r = 0.35) in one study. Floor and ceiling effects were minimal. Cronbach's alpha values were 0.82 and 0.87, respectively, confirming internal consistency reliability. Correlations with the International Restless Legs Syndrome Study Group's severity rating scale (International Restless Legs Scale; IRLS) were moderate (r = -0.68 and -0.67, respectively; p < 0.0001). The RLSQoL was able to discriminate between levels of sleep problems (p < 0.0001) and between levels of global health status determined by a Clinical Global Impression of severity (CGI-S) (p < 0.0001). Responsiveness was demonstrated by significant differences in overall life impact change scores between CGI improvement levels after 12 weeks (p < 0.0001). CONCLUSION: The RLSQoL is a valid, reliable and responsive measure of quality of life for patients with RLS, in a clinical trial setting where group comparisons are anticipated

The reliability, validity and responsiveness of the Restless Legs Syndrome Quality of Life questionnaire (RLSQoL) in a trial population-2

<p><b>Copyright information:</b></p><p>Taken from "The reliability, validity and responsiveness of the Restless Legs Syndrome Quality of Life questionnaire (RLSQoL) in a trial population"</p><p>Health and Quality of Life Outcomes 2005;3():79-79.</p><p>Published online 5 Dec 2005</p><p>PMCID:PMC1322229.</p><p>Copyright © 2005 Abetz et al; licensee BioMed Central Ltd.</p>k 12. p < 0.0001 for comparisons of the change in RLSQoL overall life impact scores among CGI-I groups in both TREAT RLS 1 and 2 (Kruskall-Wallis test). The sample size of n = 1 in the 'worsened' group in TREAT RLS 2 meant that effect sizes could not be calculated. RLSQoL = RLS Quality of Life questionnaire. CGI-I = Clinical Global Impression 'Improvement'

The reliability, validity and responsiveness of the Restless Legs Syndrome Quality of Life questionnaire (RLSQoL) in a trial population-1

<p><b>Copyright information:</b></p><p>Taken from "The reliability, validity and responsiveness of the Restless Legs Syndrome Quality of Life questionnaire (RLSQoL) in a trial population"</p><p>Health and Quality of Life Outcomes 2005;3():79-79.</p><p>Published online 5 Dec 2005</p><p>PMCID:PMC1322229.</p><p>Copyright © 2005 Abetz et al; licensee BioMed Central Ltd.</p> borderline ill patients; subgroups 3–5 include mild, moderate, and markedly ill patients; and subgroups 6–7 include severely ill, and the most extremely ill patients. p < 0.0003 (Kruskall-Wallis test comparing all three subgroups) and p < 0.000.1 (Mann-Whitney-Wilcoxon test comparing subgroups 3–5 with 6–7) for comparisons of RLSQoL overall life impact scores among collapsed CGI-S subgroups in both TREAT RLS 1 and 2; p = not significant (Mann-Whitney-Wilcoxon test comparing subgroups 1–2 with 3–5). RLSQoL = RLS Quality of Life questionnaire. CGI-S = Clinical Global Impression 'Severity of Illness'

The reliability, validity and responsiveness of the Restless Legs Syndrome Quality of Life questionnaire (RLSQoL) in a trial population-0

<p><b>Copyright information:</b></p><p>Taken from "The reliability, validity and responsiveness of the Restless Legs Syndrome Quality of Life questionnaire (RLSQoL) in a trial population"</p><p>Health and Quality of Life Outcomes 2005;3():79-79.</p><p>Published online 5 Dec 2005</p><p>PMCID:PMC1322229.</p><p>Copyright © 2005 Abetz et al; licensee BioMed Central Ltd.</p>scores among sleep problems severity groups defined by taking tertile scores for the Sleep Problems Index II in TREAT RLS 1 and 2 (Kruskall-Wallis test). RLSQoL = RLS Quality of Life questionnaire

The reliability, validity and responsiveness of the International Restless Legs Syndrome Study Group rating scale and subscales in a clinical-trial setting. Sleep Med

Abstract Patients and methods: To assess the reliability, validity, and responsiveness of the International Restless Legs Syndrome Study Group&apos;s rating scale (the International Restless Legs Scale (IRLS)) (V2.0), using pooled data from two matching, placebo-controlled studies of ropinirole for treating Restless Legs Syndrome (RLS). Results: Pooled patient samples comprised 550 patients in the baseline (validation) sample and 439 patients in the week 12 longitudinal (responsiveness) sample. Factor analysis revealed acceptability of the IRLS total score (accounting for 40% of the variance) and that nine of the 10 IRLS items could also be assigned to two distinct subscales, the symptoms or symptoms impact subscales. The IRLS total score, symptoms and symptoms impact subscales had acceptable construct validity, internal consistency reliability (aZ0.81, 0.80, and 0.76, respectively), and concurrent validity (rZK0.68, K0.52, K0.70, respectively, with the Restless Legs Syndrome Quality of Life questionnaire (RLSQoL) overall life impact score). IRLS scores differed significantly between different levels of sleep problems and Clinical Global Impression (CGI) of health status (P!0.0001), indicating known groups and clinical validity, respectively. Changes in scores differed significantly among CGI &apos;global improvement&apos; levels (P!0.0001), providing evidence of responsiveness. Conclusions: The IRLS total score, symptoms, and symptoms impact subscales are reliable, valid, and responsive in a clinical trial setting.