Confiabilidade e validação do teste de marcha estacionária de 2 minutos em indivíduos com doença de Parkinson

Abstract

Objective: This study aimed to evaluate the test-retest and interrater reliability of the 2-minute Step Test (2MST) and its validation in the population with Parkinson's disease (PD). Materials and methods: Two previously trained examiners applied the 2MST in two different moments, with an interval of 7 to 14 days between them. In addition, clinical measurements of PD were carried out using the following instruments: Berg Balance Scale (BBS), Unified PD Rating Scale (UPDRS), Hoehn and Yahr Scale (HY), gait speed and cadence, test sitting and standing up 5 times (TSS5T) and Timed Up and Go (TUG). Regarding statistical analysis, the intraclass correlation coefficient was used to measure reliability and the Pearson and Spearman correlation coefficients were used to correlate TME2 with other clinical tests (significance level assumed to be 5%). The agreement between the measurement taken at the time and the measurement recorded later via video was assessed via Bland-Altman graphs. Results: The 2MST showed high test-retest reliability (intraclass correlation coefficient [ICC] = 0.80, standard error of measurement [SEM] = 10.59, minimum detectable difference [MDD] = 29.35), as well as interexaminer ( ICC = 0.93, SEM = 4.49, MMD = 12.46). There was acceptable agreement between assessments made with in-person and video examiners, through analysis of Bland-Altman graphs. All instruments showed a statistically significant correlation with 2MST, except HY and TSS5T. A correlation magnitude above 0.50 was found between 2MST and gait speed, and a correlation magnitude between 0.30 and 0.50 with EEB, gait cadence, UPDRS and TUG, thus confirming the construct validity. Conclusion: The 2MST proved to be a highly reliable tool for evaluating functional capacity in patients with PD, with the construct validity also being proven based on its correlation with gait speed and cadence, UPDRS, EEB and TUG.