Validity and test-retest reliability of a disability questionnaire for essential tremor

• Published in: Movement disorders 2000-05, Vol.15 (3), p.516-523
• Main Authors: Louis, Elan D., Barnes, Livia F., Wendt, Kristin J., Albert, Steven M., Pullman, Seth L., Yu, Qiping, Schneier, Franklin R.
• Format: Article
• Language: English
• Subjects: Activities of Daily Living - classification; Aged; Aged, 80 and over; Biological and medical sciences; Disability; Disability Evaluation; Essential tremor; Essential Tremor - diagnosis; Female; Humans; Male; Medical sciences; Middle Aged; Motor Skills; Nervous system (semeiology, syndromes); Nervous system as a whole; Neurology; Questionnaire; Reliability; Reproducibility of Results; Validity
• ISSN: 0885-3185; 1531-8257
• DOI: 10.1002/1531-8257(200005)15:3<516::AID-MDS1015>3.0.CO;2-J

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 video‐ taped 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