Speech-language therapy is known to improve outcomes in post-stroke aphasia, particularly when it is high intensity (Brady et al., 2016). However, intensity is a multifactorial treatment parameter that is determined by several factors, including dosage amount, dosage frequency, session duration, and total intervention duration (Baker, 2012; Cherney, 2012; Warren et al., 2007). The aim of the current study was to examine the association between one such intensity sub-parameter – dosage frequency – and change in performance after 10 weeks of self-managed therapy.

Anonymized data from 2,252 post-stroke survivors who used the Constant Therapy application between late 2016 - 2019 were analyzed. The following variables were extracted: age, time since stroke, sex, baseline severity, and dosage frequency. Dosage frequency was defined as median days/week of app usage over the 10-week therapy period, binned into categories of 1, 2, 3, 4, or 5+ days/week. The outcome variable of interest was domain score, a composite performance measure reflecting overall accuracy and task difficulty. Data were analyzed using linear mixed-effects models.

Model results revealed significant main effects of time, time since stroke, baseline severity, and dosage frequency on domain score in the 10-week treatment period. Crucially, the time*dosage frequency interaction was also significant, with greater change over time for higher versus lower dosage groups. Post-hoc comparisons revealed significantly greater performance change for users who practiced 4 or 5+ days/week compared with users who practiced 1, 2 or 3 days/week.

Study results demonstrate that increased dosage frequency is associated with greater therapy gains over a 10-week treatment period of self-managed teletherapy. This result provides preliminary evidence to help guide clinicians in their recommendations to patients regarding optimal practice frequency for self-managed therapies.