Impact of atrial fibrillation and oral anticoagulation on hospital costs and length of stay.

Purpose: The results of a study assessing hospital length of stay (LOS) and inpatient costs associated with nonvalvular atrial fibrillation (AF) and AF-related warfarin use during hospitalization are presented.

Methods: Managed care administrative claims data were used to construct cohorts of patients hospitalized with AF as a primary (n = 1,868) or secondary (n = 11,200) discharge diagnosis and control groups of patients with similar demographics and clinical characteristics who were hospitalized during the same period (2002-07). Multivariate regression analyses were performed to estimate the incremental impact of AF on hospital LOS and costs per admission, as well as the incremental impact of in hospital warfarin use on the evaluated LOS and cost outcomes.

Results: The cohort of patients with AF as a secondary discharge diagnosis had a mean LOS 1.84 days greater (p < 0.001) and a mean hospital costs $3,146 higher (p < 0.001) than the control cohort; in hospital warfarin use in those patients was associated with a mean increase in LOS of 1.45 days (p < 0.001) and a mean increase in hospital costs of $1,761 per admission (p < 0.001). In the cohort of patients with AF as a primary discharge diagnosis, inpatient warfarin therapy was also associated with longer hospital stays (mean increase, 1.26 days; p < 0.001) and higher hospital costs (mean increase, $678; p = 0.031).

Conclusion: Hospitalizations of patients with a secondary diagnosis of AF are significantly longer and more costly than those of patients without a secondary diagnosis of AF, especially when warfarin is used during the hospital stay. Among patients with a primary diagnosis of AF, warfarin therapy during hospitalization is associated with significant increases in mean LOS and hospital costs.