HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) All Versions of this Article: 01.wnl.0000319693.10338.b9v1 71/20/1572    most recent Correspondence: Submit a response Alert me when this article is cited Alert me when Correspondence are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Faught, E. Articles by Cunnington, M. C. Search for Related Content PubMed PubMed Citation Articles by Faught, E. Articles by Cunnington, M. C. Related Collections Cohort studies All Epilepsy/Seizures Antiepileptic drugs

Nonadherence to antiepileptic drugs and increased mortality

Findings from the RANSOM Study

From the University of Alabama at Birmingham Epilepsy Center and Department of Veterans’ Affairs Medical Center (E.F.); Analysis Group, Inc. (M.S.D., J.R.W., A.G.), Boston, MA; and GlaxoSmithKline (M.C.C.), Harlow, UK.

Address correspondence and reprint requests to Dr. Edward Faught, Director, UAB Epilepsy Center, Civitan International Research Center 312, 1719 6th Avenue South, Birmingham, AL 35294 faught{at}uab.edu

Objectives: The primary objective was to investigate whether nonadherence to antiepileptic drugs (AEDs) is associated with increased mortality and the secondary objective to examine whether nonadherence increases the risk of serious clinical events, including emergency department (ED) visits, hospitalizations, motor vehicle accident (MVA) injuries, fractures, and head injuries.

Methods: A retrospective open-cohort design was employed using Medicaid claims data from Florida, Iowa, and New Jersey from January 1997 through June 2006. Patients aged 18 years with 1 diagnosis of epilepsy by a neurologist and 2 AED pharmacy dispensings were selected. Medication possession ratio (MPR) was used to evaluate AED adherence on a quarterly basis with MPR 0.80 considered adherent and <0.80 nonadherent. The association of nonadherence with mortality was assessed using a time-varying Cox regression model adjusting for demographic and clinical confounders. Incidence rates for serious clinical events were compared between adherent and nonadherent quarters using incidence rate ratios (IRRs) with 95% CIs calculated based on the Poisson distribution.

Results: The 33,658 study patients contributed 388,564 AED-treated quarters (26% nonadherent). Nonadherence was associated with an over threefold increased risk of mortality compared to adherence (hazard ratio = 3.32, 95% CI = 3.11–3.54) after multivariate adjustments. Time periods of nonadherence were also associated with a significantly higher incidence of ED visits (IRR = 1.50, 95% CI = 1.49–1.52), hospital admissions (IRR = 1.86, 95% CI = 1.84–1.88), MVA injuries (IRR = 2.08, 95% CI = 1.81–2.39), and fractures (IRR = 1.21, 95% CI = 1.18–1.23) than periods of adherence.

Conclusion: These findings suggest that nonadherence to antiepileptic drugs can have serious or fatal consequences for patients with epilepsy.

Abbreviations: AED = antiepileptic drug; CCI = Charlson comorbidity index; ED = emergency department; HR = hazard ratio; ICD = International Classification of Disease; IRR = incidence rate ratio; MPR = medication possession ratio; MVA = motor vehicle accident; RANSOM = Research on Antiepileptic Non-adherence and Selected Outcomes in Medicaid.

Editorial, page 1564

e-Pub ahead of print on June 18, 2008, at www.neurology.org.

Disclosure: This study was sponsored by GlaxoSmithKline R&D. E.F. has received support for research and other activities from GlaxoSmithKline in excess of $10,000/year, as well as honoraria from GlaxoSmithKline during the course of the study (less than $10,000/year). M.S.D., J.R.W., and A.G. are employees of Analysis Group, Inc., which has received research grants from GlaxoSmithKline. M.C.C. is a current employee of GlaxoSmithKline.

Received December 12, 2007. Accepted in final form March 31, 2008.

This article has been cited by other articles:

				D. C. Bergen Reducing the risk of epilepsy: Using the pharmacy for more than drug dispensing Neurology, November 11, 2008; 71(20): 1564 - 1565. [Full Text] [PDF]