The Influence of Socioeconomic Status on Selection of Anticoagulation for Atrial Fibrillation.

Esteban Gándara,Michelle Sholzberg,Zhan Yao,Andreas Laupacis,David N Juurlink,Tara Gomes,Muhammad M Mamdani

doi:10.1371/journal.pone.0149142

Abstract

ImportanceWithout third-party insurance, access to marketed drugs is limited to those who can afford to pay. We examined this phenomenon in the context of anticoagulation for patients with nonvalvular atrial fibrillation (NVAF).ObjectiveTo determine whether, among older Ontarians receiving anticoagulation for NVAF, patients of higher socioeconomic status (SES) were more likely to switch from warfarin to dabigatran prior to its addition to the provincial formulary.Design, Setting and ParticipantsPopulation-based retrospective cohort study of Ontarians aged 66 years and older, between 2008 and 2012.ExposureSocioeconomic status, as approximated by median neighborhood income.Main Outcomes and MeasureWe identified two groups of older adults with nonvalvular atrial fibrillation: those who appeared to switch from warfarin to dabigatran after its market approval but prior to its inclusion on the provincial formulary (“switchers”), and those with ongoing warfarin use during the same interval (“non-switchers”).ResultsWe studied 34,797 patients, including 3183 “switchers” and 31,614 “non-switchers”. We found that higher SES was associated with switching to dabigatran prior to its coverage on the provincial formulary (p<0.0001). In multivariable analysis, subjects in the highest quintile were 50% more likely to switch to dabigatran than those in the lowest income quintile (11.3% vs. 7.3%; adjusted odds ratio 1.50; 95% CI 1.32 to 1.68). Following dabigatran’s addition to the formulary, the income gradient disappeared.Conclusions and RelevanceWe documented socioeconomic inequality in access to dabigatran among patients receiving warfarin for NVAF. This disparity was eliminated following the drug’s addition to the provincial formulary, highlighting the importance of timely reimbursement decisions.

Highlights

Third party insurers generally decide which drugs they will reimburse based upon an assessment of value for money
We found that higher socioeconomic status (SES) was associated with switching to dabigatran prior to its coverage on the provincial formulary (p
Subjects in the highest quintile were 50% more likely to switch to dabigatran than those in the lowest income quintile (11.3% vs. 7.3%; adjusted odds ratio 1.50; 95% CI 1.32 to 1.68)

Summary

Introduction

Third party insurers generally decide which drugs they will reimburse based upon an assessment of value for money. Many drugs are fully funded, others are reimbursed only for patients who fulfill eligibility criteria, and others are not funded at all.[1, 2] Patients often pay out-ofpocket for drugs not covered by a third party Supporters of this approach to drug reimbursement note that all patients have equal access to drugs felt to represent good value for money, and that public resources are not well spent on drugs not deemed cost-effective.[2,3,4,5] critics suggest that it can take time for public plans to incorporate new evidence about a drug’s benefits in their decision-making. They argue that, in these instances, less affluent patients are less able to access effective new drugs when the cost incurs economic hardship.[6, 7] Data from publicly funded drug programs may provide insight into this issue

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