How do we measure dysarthria after stroke? A Systematic review to guide the Core Outcome Set for Dysarthria

Background

A consensus study to establish a Core Outcome Set for Dysarthria after stroke identified four key outcome domains that should be measured in research and clinical practice: 1) intelligibility of speech, 2) ability to participate in conversations, 3) living well with dysarthria, 4) communication partners skills and knowledge (where relevant). This study aimed to systematically identify corresponding measurement instruments and to examine their clinical utility and psychometric properties.

Methods

Systematic review conducted in alignment with PRISMA guidelines. Two searches were conducted: i) an update of the search strategy for the Cochrane systematic review of interventions for non-progressive dysarthria to identify instruments used in therapy trials and ii) database (CINAHL, EMBASE, MEDLINE, PsycInfo, Pubmed) searches for all post-stroke dysarthria measurement instruments. Records were screened independently. Psychometric data was extracted from included studies and methodological quality was evaluated using COSMIN and COMET guidance. Assessment of clinical utility followed OMERACT guidance.

Results

Following screening, 19 publications reporting 12 measurement instruments were identified. According to COSMIN standards all 19 publications were rated as having low, very low or unknown quality of evidence. Three measurement instruments were identified as having the most relevant clinical utility to the population, the highest quality of evidence and had the potential to measure some specific aspects from 3 of the 4 agreed domains, intelligibility, conversations and living well with dysarthria from the patient and clinician perspective. These were the Frenchay Dysarthria Assessment II, The Communication Outcomes After Stroke Scale and the Therapy Outcome Measures for Dysarthria.

Conclusions

This review provides a comprehensive overview and appraisal of dysarthria measurement instruments. Many dysarthria measurement instruments were developed for non-stroke populations including progressive dysarthria with limited psychometric data for stroke. Measurement instruments with uncertain quality of evidence can be considered for inclusion with a Core Outcome Set and three have been suggested. There is a need for further psychometric testing of these and the development of new measurement instruments to cover all aspects of intelligibility, conversations, living well with dysarthria and communication partner skills.