Digoxin Use and Associated Adverse Events Among Older Adults

Abstract

Background: Over the past 2 decades, guidelines for digoxin use have changed significantly. However, little is known about the national-level trends of digoxin use, hospitalizations for toxicity, and subsequent outcomes over this time period.

Methods: To describe digoxin prescription trends, we conducted a population-level, cohort study using data from IQVIA, Inc.'s National Prescription Audit (2007-2014) for patients aged ≥65 years. Further, in a national cohort of Medicare fee-for-service beneficiaries aged ≥65 years in the United States, we assessed temporal trends of hospitalizations associated with digoxin toxicity and the outcomes of these hospitalizations between 1999 and 2013.

Results: From 2007 through 2014, the number of digoxin prescriptions dispensed decreased by 46.4%; from 8,099,856 to 4,343,735. From 1999 through 2013, the rate of hospitalizations with a principal or secondary diagnosis of digoxin toxicity decreased from 15 to 2 per 100,000 person-years among Medicare fee-for-service beneficiaries. In-hospital and 30-day mortality rates associated with hospitalization for digoxin toxicity decreased significantly among Medicare fee-for-service beneficiaries; from 6.0% (95% confidence interval [CI], 5.2-6.8) to 3.7% (95% CI, 2.2-5.7) and from 14.0% (95% CI, 13.0-15.2) to 10.1% (95% CI, 7.6-13.0), respectively. Rates of 30-day readmission for digoxin toxicity decreased from 23.5% (95% CI, 22.1-24.9) in 1999 to 21.7% (95% CI, 18.0-25.4) in 2013 (P < .05).

Conclusion: While digoxin prescriptions have decreased, it is still widely prescribed. However, the rate of hospitalizations for digoxin toxicity and adverse outcomes associated with these hospitalizations have decreased. These findings reflect the changing clinical practice of digoxin use, aligned with the changes in clinical guidelines.

Keywords: Adverse drug event; Atrial fibrillation; Digoxin; Heart failure; Hospitalization; Medicare; Mortality; Prescriptions; Readmission.