Translation and Adaptation of a Dysarthria Assessment Tool to Be Used in the Sri Lankan Clinical Context

Abstract

Dysarthria is one of the common communication disorders that arises due to neuromuscular damage. To address this long-felt need of a formal Dysarthria tool to be implemented in the Sri Lankan clinical context, the Newcastle Dysarthria Assessment Tool (N-DAT) was adapted and validated using a normative sample during this research study. The adaptation and validation were done using three phases: (I) Identification of the most appropriate tool to adapt to SL context, (II) Translation and adaptation of the assessment tool, and (III) Identification of the face, content, and concurrent validity of the tool. At the end of the phase II, the original N-DAT assessment tool was translated and adapted to Sinhala language using WHO guidelines and Delphi methodology. The content was satisfactorily adapted and translated with the same conceptual meaning, semantics, idiomatic, score equivalences with one additional section related to the International Classification of Functioning model. The face validity and contented validity were confirmed with the Delphi group’s input. The normative sample exhibited a predicted negative correlation between age and speech- articulation, respiration, phonation, voice, pitch, and Diadochokinetic rates. The concurrent validity of the SLN-DAT was compared with another informal Dysarthria assessment that is used at National Hospital, Sri Lanka, and found to have high ICC for all subsystems. Each subsystem had higher Intra Class Correlation value ranging between r = 1.0 – 0.7 (p<0.01). However, this validation was done only among the normative sample where the SLN-DAT could be recommended to Sri Lanka after it was validated among the dysarthria population.