Cross-cultural adaptation and validation of the Swallowing Disturbance Questionnaire and the Sialorrhea Clinical Scale in Portuguese patients with Parkinson's disease.

INTRODUCTION

To date, no valid outcome measure has been developed in European Portuguese (EP) to evaluate the Parkinsons' Disease (PD) patients' (PwP) reports regarding their swallowing disturbances.

OBJECTIVES

The aim of this study was to translate and cross-culturally adapt the Swallowing Disturbance Questionnaire (SDQ) and the Sialorrhea Clinical Scale for PD (SCS-PD) into EP and to determine its clinimetric properties in PwP.

MATERIALS AND

METHODS

The original English SDQ and SCS-PD versions were cross-culturally adapted following recommendations established in international guidelines. The validation process involved 75 PwP and 65 healthy sex- and age-matched participants.

RESULTS

The EP versions of the SDQ and SCS-PD are equivalent to the original versions (content, depth, and scoring). Statistical analyses for the SDQ tool revealed good feasibility (missing data <5%), acceptability (no floor or ceiling effects), excellent internal consistency (Cronbach´s α = 0.95), good construct validity (78.5% revealed large to moderate loadings), moderate convergent validity (r = 0.60), good divergent validity (r = 0.40), good known-groups validity (p-value < .05) and a fair sensitivity and specificity (AUC = 0.700). Statistical analyses for the SCS-PD tool shows good feasibility, reasonable acceptability (floor effect), good internal consistency (Cronbach´s α = 0.85), good construct validity (85.7% showed between large to moderate loadings), good convergent validity (r = 0.78), good divergent validity (r = 0.39), good known groups validity (p-value < .05) and a fair sensitivity and specificity (AUC = 0.704).

CONCLUSIONS

The EP versions of the SDQ and SCS-PD maintained the characteristics of the original versions and therefore consistent tools to be used in PwP.