Retrospective study of total healthcare costs associated with chronic nonvalvular atrial fibrillation and the occurrence of a first transient ischemic attack, stroke or major bleed.

OBJECTIVE

To determine the direct healthcare costs associated with the onset of chronic nonvalvular atrial fibrillation (CNVAF), warfarin utilization and the occurrence of cerebrovascular events in a commercially-insured population.

RESEARCH DESIGN AND METHODS

This retrospective, observational cohort study utilized medical and pharmacy claims from a large, geographically diverse managed-care organization (N = 18.5 million) to identify continuously benefit-eligible CNVAF patients > or =45 years of age without prior valvular disease or warfarin use between January 1, 2001 and June 1, 2002. All patients were followed at least 6 months, until plan termination or the end of study follow-up. Stroke risk was assessed using the CHADS(2) (stroke-risk) index; warfarin use was defined as having filled at least one pharmacy claim. Inpatient and outpatient cost benchmarks were utilized to estimate total direct healthcare costs (pre- and post-AF index claim). For patients with transient ischemic attacks (TIA), ischemic stroke (IS) and major bleed (MB) total direct healthcare costs were also assessed. The limitations of this study included a descriptive retrospective study design without a comparison group or adjustment for baseline disease severity and drug exposure, as well as, the reliance upon administrative claims data and use of a standardized reference costing methodology.

RESULTS

The pre- and post-AF onset total direct healthcare costs (pmpm) for 3891 incidence CNVAF patients were $412 and $1235, respectively, a 200% increase. Of the 448 (12%) patients with a cerebrovascular event, pmpm costs post-AF ranged from $2235 to $3135 correlating with CHADS(2) stroke-risk status and exposure to warfarin. Total cohort pmpm costs pre and post event increased 24% from $3446.91 to $4262.12. Approximately 20% of all events occurred <2 days and 46% within 1 month after the index AF claim. Any warfarin exposure, regardless of CHADS(2) risk had an 18% to 29 % decrease in pmpm costs.

CONCLUSIONS

Post-AF total direct healthcare costs were 3 times greater than pre-AF costs. For those with a TIA, IS or MB, post-AF total direct healthcare costs increased 4.5 times from pre-AF costs; overall post-event costs in this cohort increased approximately 25% over pre-event costs. Nearly half of the events occurred within 1 month of a claim associated with an AF diagnosis. Warfarin exposure appeared to be associated with lower pmpm costs in this population.