Psychosocial impact of Parkinson's disease-associated dysarthria: Cross-cultural adaptation and validation of the Dysarthria Impact Profile into European Portuguese.

Aim: The present study sought to make a cross-cultural adaptation of the Dysarthria Impact Profile (DIP) for European Portuguese (EP) and validate it for use in Parkinson's disease (PD) patients.

Methods: The cross-cultural adaptation was carried out in accordance with the guidelines. The EP version of the DIP was administered to 80 people with PD, and 30 sex- and age-matched control participants. Psychometric properties, acceptability, feasibility reliability (internal consistency and intrarater agreement) and validity (construct, convergent and known-groups validity) were assessed using other assessment tools (motor disability and impairment, and voice impact).

Results: Overall, the EP-DIP final version has the same conceptual meaning, semantics, idiomatic and score equivalences as the original version. Statistical analyses showed adequate feasibility (missing data <5%), good acceptability (ceiling or floor effects <15%; high requests of assistance to complete the questionnaire), satisfactory internal consistency (Cronbach's α = 0.9), weak-to-moderate intrarater reliability, good construct validity, strong convergent validity (with the Voice Handicap Index; Spearman's P = -0.8) and good known-groups validity (between those with PD and control participants).

Conclusions: The EP-DIP version displays the salient features of a valid patient-based assessment tool used to measure the psychosocial impact of slight-to-mild dysarthria in people with PD. Geriatr Gerontol Int 2018; 18: 767-774.