The association between comorbid anxiety disorders and the risk of stroke among patients with diabetes: An 11-year population-based retrospective cohort study

Background: Diabetes and anxiety disorders are independent risk factors for stroke. However, it remains unclear whether the risk of stroke is higher among diabetic patients with comorbid anxiety than without comorbid anxiety. Therefore, the purpose of this study was to investigate the association between co-morbid anxiety and the risk of stroke among patients with diabetes. Methods: This is a retrospective cohort study. We used the National Health Insurance Research Database in Taiwan to identify a diabetes cohort with a new diagnosis of an anxiety disorder but without a history of stroke. The enrollment period was 2001-2006 with up to 11 years of follow-up data. Comorbid anxiety was defined by both a clinical diagnosis of the DSM-IV (ICD-9-CM) and prescriptions for anxiolytic medications. Propensity score matching was performed to balance the selected confounders between the anxiety-exposed group and anxiety non-exposed group. Cox-propositional hazard regression models were used to evaluate the association between comorbid anxiety and the risk of stroke. Results: Among patients with diabetes (N=40,846), an estimated 5.8% (N=2374) of patients had co-morbid anxiety disorders. Diabetic patients with comorbid anxiety were significantly associated with a higher risk of stroke compared to patients without comorbid anxiety (hazard ratio: 1.33, 95% confidence interval: 1.02-1.72). Limitations: The severity of anxiety or diabetes could not be measured from the claims data. Residual confounding may still exist. Conclusion: A significantly elevated risk of stroke was observed in association with comorbid anxiety among patients with diabetes. Psychiatrists should consider routine screening for anxiety disorders to prevent a stroke event among patients with diabetes. (C) 2016 Elsevier B.V. All rights reserved.