Patterns and predictors of discontinuation of rhythm-control drug therapy in patients with newly diagnosed atrial fibrillation.

STUDY OBJECTIVE

To assess patterns and predictors of discontinuation of rhythm-control drug therapy in managed care patients with newly diagnosed atrial fibrillation and the direct medical costs of atrial fibrillation in these patients.

DESIGN

Retrospective cohort study.

DATA SOURCE

PharMetrics Patient-Centric Database.

PATIENTS

A total of 3549 adults with a new diagnosis of atrial fibrillation between April 1, 2002, and March 31, 2006, and who had at least one claim for rhythm-control drug therapy within 6 months of the initial diagnosis.

MEASUREMENTS AND MAIN RESULTS

Discontinuation (defined as a gap in rhythm-control drug therapy coverage [days' supply] > or = 30 days) was assessed after the initiation of rhythm-control therapy. Among the 3549 patients included in the analysis, 2688 (75.7%) discontinued initial rhythm-control therapy in the first 12 months, with a median time to discontinuation of 89 days. Significant predictors of rhythm-control therapy discontinuation included cardiac arrest (odds ratio [OR] 2.24, 95% confidence interval [CI] 1.04-4.83), history of coronary artery bypass graft surgery (OR 2.03, 95% CI 1.02-4.05), valvular heart disease (OR 1.67, 95% CI 1.33-2.09), ischemic heart disease (OR 1.44, 95% CI 1.13-1.82), and severity of illness (Charlson Comorbidity Index score; OR 1.09, 95% CI 1.01-1.17). Over 12 months, 661 (18.6%) of the 3549 patients had a hospital stay and 285 (8.0%) had an emergency department visit that were related to atrial fibrillation. Total annual atrial fibrillation-related costs/patient were $6165: $3872 for inpatient costs, $1503 for outpatient costs, and $790 for pharmacy costs.

CONCLUSION

Initial rhythm-control drug therapy is associated with a high rate of discontinuation, especially early in therapy. Such rates of discontinuation will likely have an impact on the effectiveness of disease management and the quality of care in patients with atrial fibrillation.