The Influence of Bipolar Disorder on Stroke Hospitalizations: A nationwide study using Real-world Data

Abstract

Background: The association between bipolar disorder (BD) and vascular disease is consensual. However, little is known about the influence of BD on the outcomes of stroke-related hospitalizations. This study examines patients' characteristics with BD hospitalized for stroke and characterizes in-hospital complications resulting from this hospitalization. Methods: A retrospective observational study was conducted using an administrative nationwide database. Stroke-related hospitalizations were selected using ICD-9-CM codes 434.91, 430.x, 431.x, 432.0-432.9. From these, episodes with secondary diagnosis of BD were identified and 1:1 propensity score matching was used to select a group of episodes without BD. Administrative outcomes including length of stay (LoS) and in-hospital mortality were extracted. In-hospital complications and medical procedures were analyzed. Results: Overall, 460 episodes of stroke hospitalization were included, 236 of which had BD. Most were female (57.8%) and had >60 years (72.3%). Hypertension and dyslipidemia were present in 64.0% and 38.2%, respectively. LoS was 15.6±22.3 days and 47 patients died during admission. Obesity and thyroid dysfunction were significantly more prevalent in episodes with BD. Urinary tract infections were the most common in-hospital complications and were significantly more frequent among BD group(11.6% vs. 20.3%; p=0.012). The remaining outcomes did not differ significantly. Limitations: The use of secondary data, usually intended for administrative reasons instead of research, may have limited the findings. Conclusions: Some stroke risk factors were more frequently found in BD group. These might result from behavior, pharmacotherapy or pathophysiology of BD and should be considered when treating this population. Further research is required regarding in-hospital complications.