Test-retest reliability and construct validity of the King's Parkinson's Disease Pain Scale - Brazilian version.

The 14-item King's Parkinson's disease Pain Scale (KPPS) measures the frequency and intensity of various painful symptoms reported by people with Parkinson's disease (PD). For the Brazilian population, KPPS has undergone cross-cultural adaptation, but some measuring properties still need to be investigated. By evaluating the reliability and construct validity of the KPPS-Brazil, this study aims to fill this gap. The KPPS-Brazil was completed by participants with PD in two sessions. On the initial administration, participants also completed the McGill Pain Questionnaire (MPQ), Beck Depression Inventory (BDI), Parkinson's Disease Sleep Scale (PDSS), and Parkinson's Disease Quality of Life Questionnaire (PDQ-39). Test-retest reliability was calculated for each domain and total scores. The Bland-Altman plot was used to confirm the limits of the agreement. Calculations were made for the standard error of measurement (SEM) and minimum detectable change (MDC). The KPPS-Brazil and other measures were successfully completed by fifty people (30 men, 68.9 years old). Intraclass correlation coefficient (ICC) was 0.992 (95 % confidence interval [95 %CI] 0.983 - 0.996; p < 0.001), and all domains showed good to excellent levels of reliability. The SEM and MDC values were 1.09 and 3.02, respectively. These values are within the recommended range and 75 % of the hypotheses we have established are supported by our findings. KPPS-Brazil is a reliable instrument that can be used in clinical and research settings to evaluate pain in Brazilians with PD.