Convergent validation of EQ-5D-5L in patients with Parkinson's disease.
BACKGROUND
The European Quality of Life Questionnaire 5 level version (EQ-5D-5L) is a recently updated instrument to assess Health-Related Quality of Life (HRQoL) that has not been validated extensively. The main objective of this study was to evaluate the internal consistency and convergent validation of the EQ-5D-5L in a large sample of subjects with Parkinson's disease (PD).


METHODS
A cross-sectional study was carried out. Consecutive Mexican subjects with PD were included. HRQoL was assessed using the EQ-5D-5L and the PDQ-8. Validity of the EQ-5D-5L was assessed determining its association with clinical ratings of disease severity, as well as correlation with PDQ-8. Additionally, performance was evaluated along predefined groups based on clinical and demographic data of known determinants of quality of life.


RESULTS
A total of 585 patients were included for this study. A strong correlation was found between EQ-5D-5L index and PDQ-8 index (Spearman's correlation coefficient=-0.75; p<0.001). Correlation between EQ-5D-5L index and PDQ-8 index remained strong (-0.60 to -0.78; p values <0.001) through all predefined groups. EQ-5D-5L scored higher in those patients with dyskinesia, wearing off, freezing, postural instability, cognitive impairment or depressive mood (p values <0.001).


CONCLUSIONS
The EQ-5D-5L is a valid instrument for evaluating HRQoL in PD, performing adequately irrespective of heterogeneous clinical and demographic characteristics, and showing to be sensitive to features of advanced disease and treatment complications.
Clinical Neurodegenerative Research Unit, National Institute of Neurology and Neurosurgery, Mexico City, Mexico.
Alonso
A
Alvarado-Bolaños
Clinical Neurodegenerative Research Unit, National Institute of Neurology and Neurosurgery, Mexico City, Mexico.
Amin
A
Cervantes-Arriaga
Clinical Neurodegenerative Research Unit, National Institute of Neurology and Neurosurgery, Mexico City, Mexico; Movement Disorder Clinic, National Institute of Neurology and Neurosurgery, Mexico City, Mexico. Electronic address: mrodriguez@innn.edu.mx.
Mayela
M
Rodríguez-Violante
Clinical Neurodegenerative Research Unit, National Institute of Neurology and Neurosurgery, Mexico City, Mexico; Movement Disorder Clinic, National Institute of Neurology and Neurosurgery, Mexico City, Mexico.
Rodrigo
R
Llorens-Arenas
Clinical Neurodegenerative Research Unit, National Institute of Neurology and Neurosurgery, Mexico City, Mexico; Movement Disorder Clinic, National Institute of Neurology and Neurosurgery, Mexico City, Mexico.
Humberto
H
Calderón-Fajardo
Department of Neurology, General Hospital, Zacatecas, Zacatecas, Mexico.
Roxanna
R
Millán-Cepeda
Department of Neurology, General Hospital, Mérida, Yucatan, Mexico.
Roberto
R
Leal-Ortega
Movement Disorder Clinic, Hospital Universitario, Monterrey, Nuevo Leon, Mexico.
Ingrid
I
Estrada-Bellmann
Movement Disorder Clinic, Hospital Civil, Guadalajara, Jalisco, Mexico.
Carlos
C
Zuñiga-Ramírez
D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008800:Mexico; D008875:Middle Aged; D010300:Parkinson Disease / Q000175:diagnosis*; D011594:Psychometrics / Q000295:instrumentation*; D011788:Quality of Life; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires / Q000592:standards*
EQ-5D-5L; European Quality of Life Questionnaire; Health-related quality of life; Movement disorders; PDQ-8; Parkinson's disease; Parkinsonism; Validation