Translation, Cross-Cultural Adaptation, and Validation of the Parkinson's Disease Quality of Life Questionnaire (PDQL), the “PDQL-BR”, into Brazilian Portuguese

Abstract

Translate, culturally adapt, and validate the “Parkinson's Disease Quality of Life” (PDQL) BR, into Brazilian Portuguese. Fifty-two patients answered the PDQL-BR. Twenty-one patients answered the PDQL-BR again 14 days later. The UPDRS and HY scale was applied. Validation was evaluated using psychometric properties, checking the quality of the data, reliability, and validity. Quality of the data was evaluated based on occurrence of ceiling and floor effects. Reliability was evaluated based on: internal consistency of an item, homogeneity, and reproducibility. Validation was checked through the evaluation of convergent and discriminatory validation. There was no ceiling and floor effect. When evaluating reliability, items 20, 30, and 37 showed correlation of 0.34, 0.26, and 0.37, respectively, to your scale; the other items was higher than 0.4. The alpha Cronbach coefficient was higher than 0.7 for most domains. There was good reproducibility. There were no meaningful changes in the PDQL-BR translation and cross-cultural adaptation.

Reliability and Validity of 39-Item Parkinson’s Disease Questionnaire and Parkinson’s Disease Quality of Life Questionnaire

“…10,11 The internal consistency of the Portuguese PDQ-39 dimensions was in general equivalent to that previously reported and indicative of acceptable reliability. 9,11,12 Although in previously reported data the internal consistency of the PDQ-39 social support dimension proved to be weak, in our study bodily discomfort appeared as the less consistent dimension.…”

“…Analysing pairwise comparisons, parkinsonian symptoms and systemic symptoms, had lower scores as the disease advanced, corroborating previously reported data. 10,14 However, emotional function dimension was not able to distinguish between intermediate stages.…”

“…8,10,14,30 These differences are better attributed to differences in the socio-cultural characteristics of the sample and, perhaps, in the distinct grades of disease's severity. 10,14 Also, analyzing test-retest for PDQ-39, once again stigma and bodily discomfort did not achieve the standard criteria, suggesting that these dimensions may not provide accurate data. However, in other studies, the social support has been pointed as a weak domain.…”

“…12,27 Overall PDQL dimensions met the standard 27 The evaluation of reproducibility performed by Campos et al, using Mann-Whitney test, reported no statistically significant differences between the average scores of the two PDQL applications (Table 6). 10 In the evaluation of the construct validity of the PDQ-39, most of the dimensions were able to discriminate patients at different mH&Y stages, with scores trending in the right direction, as the majority of the scores increased with mH&Y stages. The major exceptions were emotional well-being, stigma and social support, all of them previously reported in other studies as non significant.…”

“…1,8,9 Since issues of HRQoL became a major concern for patient counselling, several validation studies for these scales have been published. [10][11][12][13][14][15] However, despite PDQ-39 and PDQL were frequently used in current clinical practice, these scales were not validated for the particular Portuguese socio-cultural setting, which may have limited the correct interpretation of the scores previously obtained.…”