Tradução, Adaptação Cultural e Validação do Parkinson s Disease Quality of Life-questionnaire (PDQL) para o português falado no Brasil, o PDQL-BR

Abstract

Parkinson is a disabling neurodegenerative disease. It is also invariably progressive. The more severe the disease, the worse patients perceive their quality of life (QL). In order to quantify the impact of the disease in the QL of these patients, QL measurement instruments have been developed. However, they need to be translated, culturally adapted and validated in order to be used in our environment. The objective of this study was to translate, culturally adapt and validate the Parkinson disease Quality of Life (PDQL) - the PDQL- BR, an assessment instrument of Health-related Quality of Life (HRQL) specific for the Parkinson Disease (PD). Method: 52 patients answered the PDQL-BR, the Beck Depression Inventory (BDI) and a questionnaire with sociodemographic data. Twenty-one patients answered the PDQL-BR again after 14 days. The Unified Parkinson s Disease Rating Scales (UPDRS) and the modified Hoehn and Yahr scale were also applied. The psychometric properties of the PDQL-BR were assessed by examining data quality, reliability and instrument validity. Data quality was assessed by the occurrence of floor and ceiling effects and the percentage of missing data. Reliability was assessed by internal consistency of the item, internal consistency reliability (homogeneity of the data) and reproducibility of the instrument. Validity was assessed by the convergent and discriminant validity. Results: There were no floor and ceiling effects. For the assessment of the internal consistency, the items 20, 30 and 37 presented correlation coefficient of 0.34; 0.26 and 0.37, respectively. Correlation coefficients for the other items were above 0.4. The α-Cronbach s coefficient was above 0.65 for all domains and 0.93 for the instrument as a whole. Scores of the PDQL-BR between the two applications were statistically similar. For the assessment of the discriminant validity, scores of the instrument and of domains of parkinsonian and systemic symptoms were different for each stage of the disease, being worse for the more advanced ones. For the assessment of the convergent validity, the emotional function domain showed a strong association with the UPDRS and BDI scales (correlation coefficients of 0.59 and 0.56, respectively). The domain Parkinsonian symptoms showed a strong correlation with the UPDRS (coefficient correlation of 0.78). Conclusion: The translated version of PDQL did not show significant change in the process of translation and cultural adaptation. Its psychometric properties were similar to those of the original instrument. Careful interpretation must be given to the evaluation of responses of items 20, 30 and 37.