Advertisement

Trouble Getting Started: Predictors of Primary Medication Nonadherence

      Abstract

      Background

      Patient nonadherence to prescribed medication is common and limits the effectiveness of treatment for many conditions. Most adherence studies evaluate behavior only among patients who have filled a first prescription. The advent of electronic prescribing (e-prescribing) systems provides the opportunity to track initial prescriptions and identify nonadherence that may have previously been undetected.

      Methods

      We analyzed e-prescribing data and filled claims for all patients with CVS Caremark (Woonsocket, RI) drug coverage who received e-prescriptions from the iScribe e-prescribing system in calendar 2008. We matched e-prescriptions with filled claims by using data on the drug name, date of e-prescription, and date of filled claims, allowing up to 180 days for patients to fill e-prescriptions. We evaluated the rate of primary nonadherence to newly prescribed medications across multiple characteristics of patients, prescribers, and prescriptions and developed multivariable models to identify predictors of nonadherence.

      Results

      We identified 423,616 e-prescriptions for new medications, with 3634 prescribers and 280,081 patients. The primary nonadherence rate was 24.0%. Several factors were associated with nonadherence to e-prescriptions, including nonformulary status of medications (odds ratio [OR] 1.31 compared with preferred medications; 95% confidence interval [CI], 1.26-1.36; P<.001) and residence in a low-income ZIP code (OR 1.23 compared with high-income ZIP code; 95% CI, 1.17-1.30; P<.001) Nonadherence occurred less often when e-prescriptions were transmitted directly to the pharmacy rather than printed to give to patients (OR 0.54; 95% CI, 0.52-0.57; P<.001).

      Conclusion

      24% of e-prescriptions for new medications were not filled. Our results suggest that interventions to address economic barriers and increase electronic integration in the healthcare system may be promising approaches to improve medication adherence.

      Keywords

      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'

      Subscribe:

      Subscribe to The American Journal of Medicine
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect

      References

        • Ho P.M.
        • Rumsfeld J.S.
        • Masoudi F.A.
        • et al.
        Effect of medication nonadherence on hospitalization and mortality among patients with diabetes mellitus.
        Arch Intern Med. 2006; 166: 1836-1841
        • Ho P.M.
        • Spertus J.A.
        • Masoudi F.A.
        • et al.
        Impact of medication therapy discontinuation on mortality after myocardial infarction.
        Arch Intern Med. 2006; 166: 1842-1847
        • Sokol M.C.
        • McGuigan K.A.
        • Verbrugge R.R.
        • Epstein R.S.
        Impact of medication adherence on hospitalization risk and healthcare cost.
        Med Care. 2005; 43: 521-530
        • Caro J.J.
        • Salas M.
        • Speckman J.L.
        • Raggio G.
        • Jackson J.D.
        Persistence with treatment for hypertension in actual practice.
        CMAJ. 1999; 160: 31-37
      1. Enhancing Prescription Medicine Adherence: A National Action Plan.
        (Accessed May 26, 2010)
        • Beardon P.H.G.
        • McGilchrist M.M.
        • McKendrick A.D.
        • McDevitt D.G.
        • MacDonald T.M.
        Primary non-compliance with prescribed medication in primary care.
        BMJ. 1993; 307: 846-848
        • Benner J.
        • Glynn R.
        • Mogun H.
        • Neumann P.
        • Weinstein M.
        • Avorn J.
        Long-term persistence in use of statin therapy in elderly patients.
        JAMA. 2002; 288: 455-461
        • Chapman R.H.
        • Benner J.S.
        • Petrilla A.A.
        • et al.
        Predictors of adherence with antihypertensive and lipid-lowering therapy.
        Arch Intern Med. 2005; 165: 1147-1152
        • Partridge A.
        • Wang P.
        • Winer E.
        • Avorn J.
        Non-adherence to adjuvant tamoxifen therapy in women with primary breast cancer.
        J Clin Oncol. 2003; 21: 602-606
        • Partridge A.H.
        • Avorn J.
        • Wang P.S.
        • Winer E.P.
        Adherence to therapy with oral antineoplastic agents.
        J Natl Cancer Inst. 2002; 94: 652-661
        • Siegel D.
        • Lopez J.
        • Meier J.
        Antihypertensive medication adherence in the Department of Veterans Affairs.
        Am J Med. 2007; 120: 26-32
        • Ekedahl A.
        • Mansson N.
        Unclaimed prescriptions after automated prescription transmittals to pharmacies.
        Pharm World Sci. 2004; 26: 26-31
        • Fischer M.A.
        • Stedman M.
        • Lii J.
        • et al.
        Primary medication non-adherence: analysis of 195,930 electronic prescriptions.
        J Gen Intern Med. 2010; 25: 284-290
        • Karter A.J.
        • Parker M.M.
        • Moffet H.H.
        • et al.
        New prescription medication gaps: a comprehensive measure of adherence to new prescriptions.
        Health Serv Res. 2009; 44: 1640-1661
        • Shah N.R.
        • Hirsch A.G.
        • Zacker C.
        • Taylor S.
        • Wood G.C.
        • Stewart W.
        Factors associated with first-fill adherence rates for diabetic medications: a cohort study.
        J Gen Intern Med. 2008; 24: 233-237
        • Shah N.R.
        • Hirsch A.G.
        • Zacker C.
        • et al.
        Predictors of first-fill adherence for patients with hypertension.
        Am J Hypertens. 2009; 22: 392-396
        • Solomon M.D.
        • Goldman D.P.
        • Joyce G.F.
        • Escarce J.J.
        Cost sharing and the initiation of drug therapy for the chronically ill.
        Arch Intern Med. 2009; 169: 740-748
        • Shrank W.H.
        • Hoang T.
        • Ettner S.L.
        • et al.
        The implications of choice: prescribing generic or preferred pharmaceuticals improves medication adherence for chronic conditions.
        Arch Intern Med. 2006; 166: 332-337
        • Fischer M.A.
        • Stedman M.R.
        • Vogeli C.
        • Ferris T.G.
        • Weissman J.S.
        Uptake of electronic prescribing in community-based practices.
        J Gen Intern Med. 2008; 23: 358-363
      2. Electronic Prescribing (eRx) Incentive Program.
        (Accessed May 26, 2010)
        • Choudhry N.K.
        • Shrank W.H.
        Four-dollar generics—increased accessibility, impaired quality assurance.
        N Engl J Med. 2010; 363: 1885-1887

      Linked Article

      • Getting Started: The Benefit of Formulary Decision Support
        The American Journal of MedicineVol. 125Issue 9
        • Preview
          We read with great interest the study entitled, “Trouble Getting Started: Predictors of Primary Medication Nonadherence.”1 Fischer et al conclude that physicians' attention to formulary status and cost of medication may considerably affect adherence and recommend future study in this regard.1 We concur that patients' cost must be minimized to optimize treatment adherence and outcomes. Our own research showed that patients who were electronically prescribed cholesterol-lowering medication via an electronic health record with built-in formulary decision support were 59% more likely than those who received a handwritten prescription to reach a favorable clinical end point: achieving their low-density lipoprotein goal.
        • Full-Text
        • PDF