Most of the Quality of Life in Essential Tremor Questionnaire (QUEST) psychometric properties resulted in satisfactory values.
OBJECTIVE
This study sought to assess the psychometric attributes of the Quality of Life in Essential Tremor Questionnaire (QUEST) by undertaking an independent validation.


METHODS
This was an observational, multicenter, cross-sectional study carried out in Neurology Departments of general hospitals. The following assessments were applied: Louis Rating Scale, Clinical Assessment of Tremor, Clinical Global Impression of Severity (CGI-ET), Hospital Anxiety and Depression Scale (HADS), EQ-5D, and QUEST (Spanish version).


RESULTS
One hundred and eighteen consecutive patients were included. According to the CGI-ET, most of patients had mild (42.4%) or moderate (43.2%) impact of tremor on performing daily activities. Fully computable QUEST data were 60.2%. The QUEST Summary Index (QUEST-SI) displayed marginal floor or ceiling effect. On the whole, QUEST internal consistency and reproducibility were satisfactory (Cronbach's alpha values: 0.73-0.86; QUEST-SI intraclass correlation coefficient: 0.77). Factor analysis identified eight factors (73.6% of the variance) that could be grouped into six, relatively coincident with the questionnaire's dimensions. The QUEST-SI correlated moderately with the EQ-5D index (r(S)=-0.40), HADS-Depression (r(S)=0.39), and CGI-ET (r(S)=0.39), and strongly with the QUEST scale for self-evaluation of tremor severity (r(S)=0.63). The standard error of measurement was 8.00.


CONCLUSIONS
Apart from a substantial problem of acceptability, most of the tested psychometric attributes of the QUEST resulted satisfactory.
Martínez-Martín
Pablo
P
Area of Applied Epidemiology, National Center for Epidemiology, and Consortium for Biomedical Research in Neurodegenerative Diseases (Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas-CIBERNED), Carlos III Institute of Health, CI, Sinesio Delgado, 6, 28029 Madrid, Spain. pmartinez@isciii.es
Jiménez-Jiménez
Félix Javier
FJ
Carroza García
Esmeralda
E
Alonso-Navarro
Hortensia
H
Rubio
Lluisa
L
Calleja
Patricia
P
Díaz-Sánchez
María
M
Benito-León
Julián
J
D000203:Activities of Daily Living / Q000523:psychology*; D000328:Adult; D020329:Essential Tremor / Q000453:epidemiology / Q000523:psychology*; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D011594:Psychometrics; D011788:Quality of Life / Q000523:psychology*; D013030:Spain / Q000453:epidemiology; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D055815:Young Adult