Conclusions
poststroke, aphasia
This study described the protocol of POLAR, a recently completed, large-scale therapy trial in aphasia, and examined the immediate and longitudinal change in naming performance after treatment, as well as the predictive value of several frequently studied prognostic factors. In conclusion, we observed a substantial improvement in naming performance after 30 hr of impairment-based therapy compared to before therapy and throughout follow-up assessments 1 month and 6 months after therapy completion. The extent of language recovery was influenced by initial aphasia severity, age, and time poststroke. These results are highly encouraging as the prevalence of chronic aphasia continues to rise. The predictability of therapy response is a fundamental prerequisite for the development of personalized therapy planning in service provision in aphasia. Future studies should capitalize on these findings to substantiate a prognostication framework that can be subjected to empirical testing.