The Main Concept Analysis: Sensitivity, specificity and Inter-Rater Reliability in Dutch-Speaking People with Aphasia

Abstract

<h3>Aims</h3><p>This study aimed to assess the sensitivity, specificity and inter-rater reliability of the Dutch Main Concept Analysis (MCA), a diagnostic tool that evaluates the effectiveness and efficiency of information transfer during verbal discourse production, in people with aphasia (PWA).</p><h3>Methods</h3><p>The MCA was administered to 30 persons with aphasia (17 fluent, 13 nonfluent). Sensitivity and specificity were assessed through (1) single-subject level comparison of MCA scores to normative data, (2) group-level comparison of MCA scores between PWA and 30 age-matched controls, and (3) ROC-analysis for total main concept score (MCS; effectiveness) and total number of accurate and complete main concepts per minute (AC/min; efficiency). Furthermore, the effect of aphasia type (fluent/nonfluent) and severity on these measures was assessed using a linear regression. Discourse samples were scored by two independent raters to calculate inter-rater reliability.</p><h3>Results</h3><p>Over 85 % of PWA showed aberrant outcomes on at least four out of seven MCA outcomes based on single-subject comparison to normative data. ROC analysis revealed that MCS and AC/min are sensitive and specific measures to differentiate between discourse of PWA and unimpaired speakers. Increased aphasia severity was associated with a reduced MCS. Good to excellent inter-rater reliability was achieved for all MCA measures.</p><h3>Conclusion</h3><p>The Dutch MCA is a sensitive and specific tool, characterized by a good to excellent inter-rater reliability, for identifying impaired effectiveness and efficiency of verbal information transfer during discourse production in PWA. Aphasia severity, but not type, is a determining factor for the effectiveness of information transfer in PWA.</p>