3001 — Does Psychiatric Comorbidity Affect the Risk of Readmission for Congestive Heart Failure?

Abrams TE (CRIISP/University of Iowa), Sarrazin MV (CRIISP/University of Iowa), Rosenthal GE (CRIISP/University of Iowa)

Objectives:
Several studies have identified variables that increase the risk of 30-day re-hospitalization following a congestive heart failure (CHF) admission. However, relatively little is known about the impact of pre-existing psychiatric comorbidity on the risk of CHF-related readmission. This study sought to examine the independent effects of pre-existing psychiatric comorbidity on the risk of both all-cause and disease-specific 30-day readmission.

Methods:
Using a retrospective cohort design we identified 51,733 veterans (mean age 70.9 ± 11.4) admitted in 2004-07 to 153 VHA hospitals with a principal diagnosis of CHF (ICD-9-CM code 428). Pre-existing psychiatric comorbidity (PTSD, anxiety, depression, bipolar disorder, and schizophrenia) were identified using ICD-9-CM codes from outpatient encounters in the 12 months prior to admission. Cox proportional hazard equations were used to adjust 30-day readmission for demographics, other medical comorbidities, and admitting hospital.

Results:
We identified 23% (n = 12,101) veterans with pre-existing psychiatric comorbidity. In unadjusted analysis, patients admitted for CHF with psychiatric comorbidity had higher rates of 30-day readmission (19.9% vs. 17.6%, p < .001). In adjusted Cox hazard analysis, patients with pre-existing psychiatric disease increased the hazards for all-cause 30-day readmission (HR, 1.13 95% CI 1.07–1.19; p < .001) and for CHF-specific 30-day readmission (HR, 1.10; 95% CI 1.05–1.15; p < .001). In analysis of the individual conditions, the range of hazards for all-cause readmission was 1.00–1.25 and 0.99 – 1.23 for disease-specific readmission. Schizophrenia, depression, and anxiety accounted for the highest risk.

Implications:
In veterans admitted for CHF, pre-existing psychiatric comorbidity modestly increases the risk of both all-cause and disease-specific CHF 30-day readmission.

Impacts:
This study indicates that psychiatric disease may be a marker for more severe illness or may reflect more complex discharge planning for those with psychiatric comorbidity. Further work is needed to understand the mechanisms contributing to the increased risk of readmission associated with existing psychiatric disease.