An exploration of aphasia therapy dosage in the first six months of stroke recovery.

Aphasia research uses the length of time within rehabilitation sessions as the main measure of dosage. Few papers detail therapeutic ingredients or outline the number of times these were delivered over the treatment period. The present observational study identified therapeutic ingredients in the Very Early Rehabiltiation in SpEech (VERSE) trial and explored the dosage provided using a model of cumulative intervention intensity (CII). Therapists video recorded one therapy session per week and 53 (12%) randomly selected therapy videos were analysed. The videos were coded for number of error productions, self-corrections and type and frequency of therapist cueing. The Western Aphasia Battery Revised-Aphasia Quotient (WABR-AQ) was used for measuring patient outcome with total verbal utterances (p < 0.001) and cues used with success (p < 0.001) being independent positive predictors of WABR-AQ score at six months post stroke and hypothesized as key therapeutic ingredients. The CII was calculated by counting identified therapeutic ingredients and multiplying this by the number of sessions completed. Collectively, the key ingredients occurred on average 504 times per session and over 10,000 times per participant during the treatment period. This paper reports a novel approach for identifying key treatment ingredients and detailing the dosage delivered within an early aphasia rehabilitation trial.