Análise das Propriedades de Medida da King's Parkinson's Disease Pain Scale (KPPS-Brasil) e do Activities of Daily Living Questionnaire (ADLQ-Brasil) para indivíduos com a Doença de Parkinson

Abstract

Introduction: Pain is a very prevalent and disabling symptom in Parkinson’s disease (PD). Along with this symptom, the disease's motor alterations related to other non-motor symptoms may cause it difficult to perform activities of daily living (ADL). Therefore, it is critical to assess pain using a specific tool capable of classifying the several types of pain present in PD as well as evaluating the patient's perceived ability to do ADL. Instruments with adequate measuring properties and clinical utility are required for this. Objective: To investigate the measurement properties of the King’s Parkinson’s Disease Pain Scale (KPPS-Brazil) and the Activities of Daily Living Questionnaire (ADLQ-Brazil). Methods: This methodological study investigated the test-retest reliability and construct validity of the KPPS-Brazil and the ADLQ-Brazil in people with PD in accordance with the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN). Fifty patients (30 men, mean age 68±9.5 years) were evaluated in two moments (test and retest), with an interval of 7 to 10 days. KPPS-Brazil and ADLQ-Brazil were applied in the test and retest, and the application of the ADLQ in the retest was carried out through telephone contact. Body structure and function components were assessed (pain: McGill Questionnaire; depressive symptoms: Beck Depression Inventory, BDI; fatigue: Modified Fatigue Impact Scale, MFIS; sleep disorders: Parkinson’s Disease Sleep Scale, PDSS; apathy: Apathy Scale and balance: MiniBESTest), activity (digital dexterity: Nine Hole Peg Test, 9- HPT; mobility: Timed Up and Go, TUG, including dual task and functional capacity: Moviment Disorder Society-sponsored revision of the Unified Parkinson's Disease Rating Scale , MDS-UPDRSII) and participation (quality of life: The 39 item Parkinson’s Disease Questionnaire, PDQ-39). Test-retest reliability was assessed by kappa (k) statistics for individual KPPS items and by intraclass correlation coefficient (ICC) for individual ADLQ items and total scores of both instruments. The measurement standard error (SEM) and the minimum detectable change (DMC) were also calculated and the Bland-Altman graph was analyzed for agreement analysis. For the assessment of construct validity, predefined hypotheses were created to estimate the strength of correlations between the KPPS and ADLQ scores and measures of body structure and function, activity and participation using Spearman's correlation coefficients. Results: A high level of agreement was found between the total KPPS scores obtained in both applications (ICC = 0.992; CI 95%=0.983–0.996). For the domains, 57% had very high reliability (ICC > 0.90) and 43% had high reliability (ICC > 0.75). SEM (1.09) and DMC (3,02) showed clinically acceptable values. Of the established hypotheses, 83% were confirmed, indicating adequate KPPS-Brazil construct validity. For the ADLQ, a high level of agreement was also found for the total scores (ICC = 0.997; 95% CI=0.994–0.998). Nineteen items had almost perfect agreement (k=0.81–1.0) and one of them had perfect reliability (k=1.0). SEM (2.16) and DMC (5.9) showed clinically acceptable values. Regarding the established hypotheses, 100% were confirmed, indicating adequate construct validity of the ADLQ-Brazil. Conclusions: Both the KPPS-Brazil and the ADLQ-Brazil were found to be valid and reliable for evaluating pain and ADL performance in individuals with PD, respectively.