Treatment dose in post-stroke aphasia: A systematic scoping review.

Little is known about how the amount of treatment a person with aphasia receives impacts aphasia recovery following stroke, yet this information is vital to ensure effective treatments are delivered efficiently. Furthermore, there is no standard dose terminology in the stroke rehabilitation or aphasia literature. This scoping review aims to systematically map the evidence regarding dose in treatments for post-stroke aphasia and to explore how treatment dose is conceptualized, measured and reported in the literature. A comprehensive search was undertaken in June 2019. One hundred and twelve intervention studies were reviewed. Treatment dose (amount of treatment) has been conceptualized as both a measure of time and a count of discrete therapeutic elements. Doses ranged from one to 100 hours, while some studies reported session doses of up to 420 therapeutic inputs per session. Studies employ a wide variety of treatment schedules (i.e., session dose, session frequency, and intervention duration) and the interaction of dose parameters may impact the dose-response relationship. High dose interventions delivered over short periods may improve treatment efficiency while maintaining efficacy. Person- and treatment-level factors that mediate tolerance of high dose interventions require further investigation. Systematic exploration of dose-response relationships in post-stroke aphasia treatment is required.