TY - JOUR
T1 - Validity and test-retest reliability of a disability questionnaire for essential tremor
AU - Louis, Elan D.
AU - Barnes, Livia F.
AU - Wendt, Kristin J.
AU - Albert, Steven M.
AU - Pullman, Seth L.
AU - Yu, Qiping
AU - Schneier, Franklin R.
PY - 2000
Y1 - 2000
N2 - Background: One important outcome in clinical trials is patients' own opinions about whether the medication alleviates their symptoms and improves their ability to function. A valid and reliable method with which to assess this subjective information is important. Objective: To determine the validity and test-retest reliability of the Columbia University Disability Questionnaire for Essential Tremor (ET). Methods: Patients with ET underwent a 2.5-hour evaluation, including a 36-item tremor disability questionnaire, to assess the functional impact of tremor, a 26-item videotaped tremor examination rated by a neurologist, a 15-item performance-based test, and quantitative computerized tremor analysis. We determined the validity and test-retest reliability of the tremor disability questionnaire. Correlations between variables were assessed using Pearson's correlation coefficients and test-retest reliability with the weighted kappa statistic. Results: Ninety-five patients with ET participated. The score on tremor disability questionnaire correlated with the neurologist's clinical ratings (r = 0.57, p <0.001) and the total score on the performance-based test (r = 0.69, p <0.001). Correlations with quantitative computerized tremor analysis results were less robust, but each remained significant, including mean amplitude of dominant arm tremor while arms were extended (r = 0.56, p <0.001), while drawing a spiral (r = 0.42, p = 0.01), and while pouring (r = 0.34, p = 0.04). The questionnaire was readministered to 32 subjects, and the test-retest reliability was substantial (weighted kappa = 0.67). Conclusions: This Tremor Disability Questionnaire demonstrated substantial reliability, and it correlated with multiple measures of tremor severity, including a neurologist's clinical ratings, a performance-based test of function, and quantitative computerized tremor analysis results. The questionnaire would be useful in clinical trials in which it could be used as a reliable and valid tool to assess disability in ET.
AB - Background: One important outcome in clinical trials is patients' own opinions about whether the medication alleviates their symptoms and improves their ability to function. A valid and reliable method with which to assess this subjective information is important. Objective: To determine the validity and test-retest reliability of the Columbia University Disability Questionnaire for Essential Tremor (ET). Methods: Patients with ET underwent a 2.5-hour evaluation, including a 36-item tremor disability questionnaire, to assess the functional impact of tremor, a 26-item videotaped tremor examination rated by a neurologist, a 15-item performance-based test, and quantitative computerized tremor analysis. We determined the validity and test-retest reliability of the tremor disability questionnaire. Correlations between variables were assessed using Pearson's correlation coefficients and test-retest reliability with the weighted kappa statistic. Results: Ninety-five patients with ET participated. The score on tremor disability questionnaire correlated with the neurologist's clinical ratings (r = 0.57, p <0.001) and the total score on the performance-based test (r = 0.69, p <0.001). Correlations with quantitative computerized tremor analysis results were less robust, but each remained significant, including mean amplitude of dominant arm tremor while arms were extended (r = 0.56, p <0.001), while drawing a spiral (r = 0.42, p = 0.01), and while pouring (r = 0.34, p = 0.04). The questionnaire was readministered to 32 subjects, and the test-retest reliability was substantial (weighted kappa = 0.67). Conclusions: This Tremor Disability Questionnaire demonstrated substantial reliability, and it correlated with multiple measures of tremor severity, including a neurologist's clinical ratings, a performance-based test of function, and quantitative computerized tremor analysis results. The questionnaire would be useful in clinical trials in which it could be used as a reliable and valid tool to assess disability in ET.
KW - Disability
KW - Essential tremor
KW - Questionnaire
KW - Reliability
KW - Validity
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U2 - 10.1002/1531-8257(200005)15:3<516::AID-MDS1015>3.0.CO;2-J
DO - 10.1002/1531-8257(200005)15:3<516::AID-MDS1015>3.0.CO;2-J
M3 - Article
C2 - 10830418
AN - SCOPUS:0034126377
VL - 15
SP - 516
EP - 523
JO - Movement Disorders
JF - Movement Disorders
SN - 0885-3185
IS - 3
ER -