Introduction: Recent evidence suggests that psychological distress, including symptoms of psychiatric illness, may acutely increase the risk of stroke. However, current studies are limited by small sample sizes, inherent recall bias, and poorly defined criteria for what constitutes psychological distress.
Methods: We used a case-crossover design, where each patient serves as his/her own control, to assess the relationship between the diagnosis of a psychiatric condition (defined by ICD-9 codes) and stroke (combined hemorrhagic and ischemic events) in adults over the age of 18. Data were utilized from the Healthcare Cost and Utilization Project (HCUP) for the state of California from 2007 - 2009. Cases in which both stroke and psychiatric diagnoses were present on arrival were excluded from the analysis. The relationship between psychiatric hospitalization and stroke was assessed through conditional logistic regression, with separate analyses conducted for 15, 30, 90, 180, and 365-days pre-stroke.
Results: A total of 52,068 strokes were identified. Psychiatric conditions diagnosed within 1 year of stroke were found in 3,337 (6.4%) patients. Compared to patients without (n = 48,731), patients with a recent psychiatric hospitalization had a higher proportion of women (59.67% vs. 50.11%) and longer hospital course (8.9 days vs. 6.9). The presence of a psychiatric condition leading to hospitalization was associated with increased odds of stroke within all five pre-defined time periods (Table 1), with the highest odds of stroke occurring in those who most recently experienced a psychiatric visit (15 day OR = 3.48, 95% CI; 2.68-4.52).
Conclusions: Psychiatric hospitalization increases the short-term risk of stroke, particularly within the 15-day period following the diagnosis. This risk decreases but persists for at least 1 year.