Assessment of Medication Adherence Using Pharmacy Data Before and After Percutaneous Coronary Intervention

Abstract

Seifu M Abera,1,2 Colin O’Donnell,3 Taufiq Salahuddin,1,2 Krishna Prabhu,4 Carol E Simons,1 P Michael Ho,5,6 Stephen W Waldo,3,5,6 Jacob A Doll1– 3 1Section of Cardiology, VA Puget Sound Health Care System, Seattle, WA, USA; 2Department of Medicine, University of Washington, Seattle, WA, USA; 3Department of Veterans Affairs Clinical Assessment, Reporting, and Tracking Program, VHA Office of Quality and Patient Safety, Washington, DC, USA; 4Hennepin County Medical Center, Minneapolis, MN, USA; 5Rocky Mountain Regional VA Medical Center, Aurora, CO, USA; 6Department of Medicine, University of Colorado School of Medicine, Aurora, CO, USACorrespondence: Jacob A Doll, VA Puget Sound Health Care System, 1660 S. Columbian Way, S111-CARDIO, Seattle, WA, 98108, USA, Tel [phone], Fax [phone], Email [email protected]: Adherence to anti-platelet medications is critical following coronary stenting, but prior studies indicate that clinician assessment and patient self-assessment of adherence are poorly correlated with future medication-taking behavior. We therefore sought to determine if integrated pharmacy data can be used to identify patients at high risk of non-adherence after percutaneous coronary interventions (PCI).Methods: Using Veteran Affairs (VA) Clinical Assessment, Reporting, and Tracking (CART) data linked with pharmacy records, we assessed adherence to cardiovascular medications from 2012 to 2018. Adherence was defined as the proportion of days covered (PDC) ≥ 0.80. We assessed the association of pre-PCI adherence with post-PCI adherence to P2Y12 inhibitors and clinical outcomes using logistic regression and Cox proportional hazard models, respectively.Results: Among 56,357 patients, 66.0% filled at least 1 cardiovascular medication within VA for the year prior to PCI and were evaluable for adherence. Pre-PCI non-adherence was 20.7%, and non-adherent patients were more likely to be younger and present non-electively. Non-adherent patients were less likely to adhere to P2Y12 inhibitor therapy after PCI (Adjusted OR 0.45 C.I. 0.41– 0.46), compared with adherent patients, and had a higher adjusted risk of mortality (HR 1.17 C.I. 1.03– 1.33).Conclusion: Adherence to cardiovascular medications prior to PCI can be assessed for most patients using pharmacy data, and past adherence is associated with future adherence and mortality after PCI. Use of integrated pharmacy data to identify high-risk patients could improve outcomes and cost-effectiveness of adherence interventions.Plain Language Summary: Why was the study done?: Non-adherence to anti-platelet medications is common following coronary stenting procedures and is associated with worse outcomes, but predicting non-adherence is challenging.What did the researchers do and find?: The researchers examined pharmacy fill-based adherence assessments before and after stenting procedures. Pharmacy data can provide adherence estimates for most patients receiving percutaneous coronary intervention, and these estimates are associated with downstream medication-taking behavior and clinical outcomes.What do the results mean?: Health systems should seek to integrate pharmacy-based adherence estimates into routine care for patients with cardiovascular disease. Identification and targeting of patients at high-risk for non-adherence may improve the impact and cost-effectiveness of future research and health policy interventions aimed at improving adherence.Keywords: percutaneous coronary intervention, medication adherence

Keywords

• percutaneous coronary intervention
• medication adherence