TY - JOUR
T1 - Reliability and validity of two self-administered questionnaires for screening restless legs syndrome in population-based studies
AU - Popat, Rita A.
AU - Van Den Eeden, Stephen K.
AU - Tanner, Caroline M.
AU - Kushida, Clete A.
AU - Rama, Anil N.
AU - Black, Jed E.
AU - Bernstein, Allan
AU - Kasten, Meike
AU - Chade, Anabel
AU - Leimpeter, Amethyst
AU - Cassidy, John
AU - McGuire, Valerie
AU - Nelson, Lorene M.
PY - 2010/2/1
Y1 - 2010/2/1
N2 - Background: A reliable and valid questionnaire for screening restless legs syndrome (RLS) is essential for determining accurate estimates of disease frequency. In a 2002 NIH-sponsored workshop, experts suggested three mandatory questions for identifying RLS in epidemiologic studies. We evaluated the reliability and validity of this RLS-NIH questionnaire in a community-based sample and concurrently developed and evaluated the utility of an expanded screening questionnaire, the RLS-EXP. Methods: The study was conducted at Kaiser Permanente of Northern California and the Stanford University Sleep Clinic. We evaluated test-retest reliability in a random sample of subjects with prior physician-assigned RLS (n = 87), subjects with conditions frequently misclassified as RLS (n = 31), and healthy subjects (n = 9). Validity of both instruments was evaluated in a random sample of 32 subjects, and in-person examination by two RLS specialists was used as the gold standard. Results: For the first three RLS-NIH questions, the kappa statistic for test-retest reliability ranged from 0.5 to 1.0, and sensitivity and specificity was 86% and 45%, respectively. For the subset of five questions on RLS-EXP that encompassed cardinal features for diagnosing RLS, kappas were 0.4-0.8, and sensitivity and specificity were 81% and 73%, respectively. Conclusions: Sensitivity of RLS-NIH is good; however, the specificity of the instrument is poor when examined in a sample that over-represents subjects with conditions that are commonly misclassified as RLS. Specificity can be improved by including separate questions on cardinal features, as used in the RLS-EXP, and by including a few questions that identify RLS mimics, thereby reducing false positives.
AB - Background: A reliable and valid questionnaire for screening restless legs syndrome (RLS) is essential for determining accurate estimates of disease frequency. In a 2002 NIH-sponsored workshop, experts suggested three mandatory questions for identifying RLS in epidemiologic studies. We evaluated the reliability and validity of this RLS-NIH questionnaire in a community-based sample and concurrently developed and evaluated the utility of an expanded screening questionnaire, the RLS-EXP. Methods: The study was conducted at Kaiser Permanente of Northern California and the Stanford University Sleep Clinic. We evaluated test-retest reliability in a random sample of subjects with prior physician-assigned RLS (n = 87), subjects with conditions frequently misclassified as RLS (n = 31), and healthy subjects (n = 9). Validity of both instruments was evaluated in a random sample of 32 subjects, and in-person examination by two RLS specialists was used as the gold standard. Results: For the first three RLS-NIH questions, the kappa statistic for test-retest reliability ranged from 0.5 to 1.0, and sensitivity and specificity was 86% and 45%, respectively. For the subset of five questions on RLS-EXP that encompassed cardinal features for diagnosing RLS, kappas were 0.4-0.8, and sensitivity and specificity were 81% and 73%, respectively. Conclusions: Sensitivity of RLS-NIH is good; however, the specificity of the instrument is poor when examined in a sample that over-represents subjects with conditions that are commonly misclassified as RLS. Specificity can be improved by including separate questions on cardinal features, as used in the RLS-EXP, and by including a few questions that identify RLS mimics, thereby reducing false positives.
UR - http://www.scopus.com/inward/record.url?scp=75149172666&partnerID=8YFLogxK
U2 - 10.1016/j.sleep.2009.01.012
DO - 10.1016/j.sleep.2009.01.012
M3 - Journal articles
C2 - 20089446
AN - SCOPUS:75149172666
SN - 1389-9457
VL - 11
SP - 154
EP - 160
JO - Sleep Medicine
JF - Sleep Medicine
IS - 2
ER -