To assess whether a patient's outpatient primary health system (PHS) changes after being admitted to a different health system for ischemic stroke.

Interhospital transfers for ischemic stroke are on the rise, particularly affecting rural patients. It's unclear whether such admissions influence future healthcare-seeking behavior.

We analyzed a 5% sample of Medicare Fee-for-Service claims for ischemic stroke admissions from 2017 to 2021, excluding patients <66 and had no continuous coverage. Each hospital was assigned to a health system using data from the AHRQ. The health system with the majority of a patient’s specialists before the stroke was defined as their “Pre-stroke PHS,” and this was reassessed two years post-stroke.  We used logistic regression to analyze the likelihood of patients changing their PHS after stroke.

We identified 21,087 patients (77.9 years old, 56% female, 86% non-Hispanic White, and 68% urban). 10.2% of patients experienced interhospital transfers, and 17.9% of those patients transferred out of their pre-stroke PHS. Out of the 14,429 patients who had both pre-stroke and post-stroke PHS data, 51% were admitted to a facility outside of their pre-stroke PHS for stroke care. Of those admitted outside their pre-stroke PHS, 70% changed their PHS after the stroke. In contrast, among patients admitted within their pre-stroke PHS, 68% continued with the same PHS after the stroke. After adjusting for patient socioeconomic and clinical characteristics, we found that patients admitted outside their PHS for stroke were significantly more likely to change their PHS post-stroke (OR 5.09, 95%CI:4.73-5.47, p<0.01). Patients who were interhospital transferred for stroke were 15% less likely to remain at their pre-stroke PHS (OR 0.84, 95% CI:0.74-0.96, p<0.01).

Admission outside of the pre-stroke PHS was associated with changes in PHS after stroke. Patients might experience disrupted continuity of care following a stroke, leading to missed follow-up appointments and inconsistent secondary prevention.