High Quality of Early Ischemic Stroke Care but Poorer Clinical Outcomes among Patients with a History of Mental Illness

Objectives. The aim of this study was to compare early stroke care and clinical outcomes among patients with and without a history of mental illness. Materials/Methods. A nationwide registry-based cohort study of patients with acute ischemic stroke treated in a tax-financed healthcare system. We used process and outcome measures from the Danish Stroke Registry 2007-2018 combined with the data from multiple Danish registries. We combined the process measures in two composite measures: an opportunity-based score (the proportion of all relevant process measures fulfilled for each patient) and an all-or-none score (the proportion of patients fulfilling all relevant process measures). Patients were categorized according to severity of mental health history. Results. We included 117 548 admissions with acute ischemic stroke: 20.8%, 3.5%, and 3.4% of admissions concerned patients with a history of minor, moderate, or major mental illness, respectively. Patients received a median of 85.7% (IQR, 66.7; 100.0) of the relevant processes (opportunity-based score). Patients with a history of mental illness were less likely to receive guideline-recommended acute stroke care within the defined time frames; however, differences were not clinically relevant. Patients with a history of mental illness were significantly more likely to die within 30 days, compared to patients with no history of mental illness: Risk ratios (RR) for 30-day mortality adjusted for age, sex, and country of origin were 1.31 (CI, 1.25; 1.37) for minor, 1.18 (CI, 1.05; 1.33) for moderate, and 1.44 (CI, 1.30; 1.60) for major mental illness. The corresponding adjusted RRs for recurrent stroke/TIA were 1.69 (CI, 1.58; 1.80) for minor, 1.39 (CI, 1.19; 1.61) for moderate, and 1.36 (CI, 1.17; 1.59) for major mental illness. The associations were weakened for 30-day mortality but not recurrent stroke/TIA after additional adjustment for potential mediating factors (comorbidity and stroke severity). Conclusion. More than one-quarter of patients with ischemic stroke had a history of mental illness. The overall performance of acute stroke care was high in all groups. Mental illness was associated with a higher risk of death and recurrent stroke compared to patients without a history of mental illness which may at least partly be due to a more adverse prognostic profile at the time of admission, including a higher stroke severity.