Does pre-existing cognitive impairment impact on amount of stroke rehabilitation received? An observational cohort study.

The study was observational and did not assign treatment, so it cannot show that cognitive impairment caused less therapy. 52 patients were not approached because no consultee was available or the clinical team advised against it, and 25 consenting participants came from a site without complete screening data, so the sample may miss people with cognitive impairment. Only 9 participants had diagnosed dementia, so dementia and undiagnosed cognitive impairment were combined; the study cannot separate their effects. Therapy sessions were counted from clinical notes, so some therapy may not have been documented, and data extraction was not blind to cognitive status. Pre-existing cognitive impairment was identified from documentation, often family social history, and not all participants had routine cognitive screening, so some impairment may have been missed. The difference became smaller after accounting for pre-stroke disability, and that measure may be confounded because cognitive impairment can affect disability scores. The study only included patients already admitted to rehabilitation, so it cannot describe differences for patients who were never referred or admitted. No post-stroke outcome measures were collected, so the study cannot show whether less therapy affected recovery.

The authors declared no potential conflicts of interest. The study was funded by the National Institute for Health Research Collaboration for Leadership in Applied Health Research and Care Greater Manchester in partnership with the Stroke Association, and one author was partially funded by the Stroke Association and that collaboration. The views expressed were the authors' and not necessarily those of the funders.

Do not read the 16 fewer sessions as proof that cognitive impairment caused unequal care. The study was observational, therapy was counted from notes, and the difference became 9 fewer after accounting for age, sex, stroke severity and pre-stroke disability.