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Effects of Increased Patient Cost Sharing on Socioeconomic Disparities in Health Care

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Abstract

Background

Increasing patient cost sharing is a commonly employed mechanism to contain health care expenditures.

Objective

To explore whether the impact of increases in prescription drug copayments differs between high- and low-income areas.

Design

Using a database of 6 million enrollees with employer-sponsored health insurance, econometric models were used to examine the relationship between changes in drug copayments and adherence with medications for the treatment of diabetes mellitus (DM) and congestive heart failure (CHF).

Subjects

Individuals 18 years of age and older meeting prespecified diagnostic criteria for DM or CHF were included.

Measurements

Median household income in the patient’s ZIP code of residence from the 2000 Census was used as the measure of income. Adherence was measured by medication possession ratio: the proportion of days on which a patient had a medication available.

Results

Patients in low-income areas were more sensitive to copayment changes than patients in high- or middle-income areas. The relationship between income and price sensitivity was particularly strong for CHF patients. Above the lowest income category, price responsiveness to copayment rates was not consistently related to income.

Conclusions

The relationship between medication adherence and income may account for a portion of the observed disparities in health across socioeconomic groups. Rising copayments may worsen disparities and adversely affect health, particularly among patients living in low-income areas.

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References

  1. National Center for Health Statistics. Health, United States, 1998 with Socioeconomic Status and Health Chartbook. Hyattsville, MD: National Center for Health Statistics; 1998.

    Google Scholar 

  2. Rao SV, Kaul P, Newby LK, et al. Poverty, process of care, and outcome in acute coronary syndromes. JACC. 2003;41(11):1948–54.

    PubMed  Google Scholar 

  3. Lemstra M, Neudorf C, Opondo J. Health disparity by neighbourhood income. Can J Public Health. 2006;97(6):435–9.

    PubMed  Google Scholar 

  4. Schneeweiss S, Soumerai SB, Glynn RJ, Maclure M, Dormuth C, Walker AM. Impact of reference-based pricing for angiotensin-converting enzyme inhibitors on drug utilization. CMAJ. 2002;166(6):737–45.

    PubMed  Google Scholar 

  5. Federman AD, Halm EA, Zhu C, Hochman T, Siu AL. Association of income and prescription drug coverage with generic medication use among older adults with hypertension. Am J Manag Care. 2006;12(10):611–8.

    PubMed  Google Scholar 

  6. Piette JD, Heisler M, Wagner TH. Problems paying out-of-pocket medication costs among older adults with diabetes. Diabetes Care. 2004;27(2):384–91.

    Article  PubMed  Google Scholar 

  7. Claxton G, Gabel J, Gil I, et al. Health benefits in 2006: premium increases moderate, enrollment in consumer-directed health plans remains modest. Health Aff. 2006;25(6):w476–85.

    Article  Google Scholar 

  8. Goldman DP, Joyce GF, Escarce JJ, et al. Pharmacy benefits and the use of drugs by the chronically ill. JAMA. 2004;291(19):2344–50.

    Article  PubMed  CAS  Google Scholar 

  9. Federman AD, Vladeck BC, Siu AL. Avoidance of health care services because of cost: impact of the medicare savings program. Health Aff. 2005;24(1):263–70.

    Article  Google Scholar 

  10. Rice T, Matsuoka KY. The impact of cost-sharing on appropriate utilization and health status: a review of the literature on seniors. Med Care Res Rev. 2004;61(4):415–52.

    Article  PubMed  Google Scholar 

  11. Goldman DP, Joyce GF, Zheng Y. Prescription drug cost sharing: associations with medication and medical utilization and spending and health. JAMA. 2007;298(1):61–9.

    Article  PubMed  CAS  Google Scholar 

  12. Schneeweiss S, Soumerai SB, Glynn RJ, Maclure M, Dormuth C, Walker AM. Impact of reference-based pricing for angiotensin-converting enzyme inhibitors on drug utilization. CMAJ. 2002;166(6):737–45.

    PubMed  Google Scholar 

  13. Pilote L, Beck C, Richard H, Eisenberg MJ. The effects of cost-sharing on essential drug prescriptions, utilization of medical care and outcomes after acute myocardial infarction in elderly patients. CMAJ. 2002;167(3):246–52.

    PubMed  Google Scholar 

  14. Hsu J, Price M, Huang J, et al. Unintended consequences of caps on medicare drug benefits. N Eng J Med. 2006;354(22):2349–59.

    Article  CAS  Google Scholar 

  15. Tamblyn R, Laprise R, Hanley JA, et al. Adverse events associated with prescription drug cost-sharing among poor and elderly persons. JAMA. 2001;285(4):421–9.

    Article  PubMed  CAS  Google Scholar 

  16. Bryson CL, Au DH, Young B, McDonell MB, Finh SD. A refill adherence algorithm for multiple short intervals to estimate refill compliance (ReComp). Med Care. 2007;45(6):497–504.

    Article  PubMed  Google Scholar 

  17. Gonnella JS, Lewis DZ, Gozum MV, Callahan CA, Barnes CA. Disease Staging: Clinical Criteria, 5th ed. Ann Arbor, MI: Thomson Medstat; 2005.

    Google Scholar 

  18. Joyce GE, Escarce JJ, Solomon MD, Goldman DP. Employer drug benefit plans and spending on prescription drugs. JAMA. 2002;288(14):1733–9.

    Article  PubMed  Google Scholar 

  19. Benner JS, Glynn RJ, Mogun H, Neumann PJ, Weinstein MC, Avorn J. Long-term persistence in use of statin therapy in elderly patients. JAMA. 2002;288(4):455–61.

    Article  PubMed  Google Scholar 

  20. Gibson TB, Mark TL, McGuigan KA, Axelsen K, Wang S. The effects of prescription drug copayments on statin adherence. Am J Manag Care. 2006;12(9):509–17.

    PubMed  Google Scholar 

  21. Cole JA, Norman H, Weatherby LB, Walker AM. Drug copayment and adherence in chronic heart failure: effect on cost and outcomes. Pharmacotherapy. 2006;26(8):1157–64.

    Article  PubMed  Google Scholar 

  22. Pladevall M, Williams LK, Potts LA, Divine G, Xi H, Lafata JE. Clinical outcomes and adherence to medications measured by claims data in patients with diabetes. Diabetes Care. 2004;27(12):2800–5.

    Article  PubMed  Google Scholar 

  23. Sokol MC, McGuigan KA, Verbrugge RR, Epstein RS. Impact of medication adherence on hospitalization risk and healthcare cost. Med Care. 2005;43(6):521–30.

    Article  PubMed  Google Scholar 

  24. Gibson TB, McLaughlin CG, Smith DG. A copayment increase for prescription drugs: the long term and short-term effects on use and expenditures. Inquiry. 2005;42(3):293–310.

    PubMed  Google Scholar 

  25. Taira DA, Wong KS, Frech-Tamas F, Chung RS. Copayment level and compliance with antihypertensive medication: analysis and policy implications for managed care. Am J Manag Care. 2006;12(11):678–83.

    PubMed  Google Scholar 

  26. Huskamp HA, Deverka PA, Epstein AM, Epstein RS, McGuigan KA, Frank RG. The effect of incentive-based formularies on prescription-drug utilization and spending. N Engl J Med. 2003;349(23):2224–32.

    Article  PubMed  CAS  Google Scholar 

  27. Soumerai SB, McLaughlin TJ, Ross-Degnan D, Casteris CS, Bollini P. Effects of a limit on Medicaid drug-reimbursement benefits on the use of psychotropic agents and acute mental health services by patients with schizophrenia. N Engl J Med. 1994;331(10):650–5.

    Article  PubMed  CAS  Google Scholar 

  28. Krieger N, Waterman P, Chen JT, Soobader MJ, Subramanian SV, Carson R. Zip code caveat: bias due to spatiotemporal mismatches between ZIP codes and US census-defined geographic areas—the Public Health Disparities Geocoding Project. Am J Pub Health. 2002;92(7):1100–2.

    Article  PubMed  Google Scholar 

  29. Fendrick AM, Smith DG, Chernew ME, Shah SN. A benefit-based copay for prescription drugs: patient contribution based on total benefits, not drug acquisition cost. Am J Manag Care. 2001;7(9):861–7.

    PubMed  CAS  Google Scholar 

  30. Chernew ME, Rosen AB, Fendrick AM. Value-based insurance design. Health Aff (Millwood). 2007;26(2):w195–203.

    Article  Google Scholar 

  31. Fendrick AM, Chernew ME. Value-based insurance design: a “clinically sensitive, fiscally responsible” approach to mitigate the adverse clinical effects of high-deductible consumer-directed health plans. J Gen Intern Med. 2007;22(6):890–1.

    Article  PubMed  Google Scholar 

  32. Freudenheim M. To save later, some employers are offering free drugs now. New York Times. February 21, 2007:A1.

    Google Scholar 

  33. Roblin DW, Platt R, Goodman MJ, et al. Effect of increased cost-sharing on oral hypoglycemic use in 5 managed care organizations: how much is too much? Med Care. 2005;43(10):951–959.

    Article  Google Scholar 

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Acknowledgments

We thank Amelito Torres for his programming assistance.

Conflict of Interest

This work was supported by financial support from GlaxoSmithKline. At the time of the study, both Dr. Sokol and Dr. Yu-Isenberg were full-time employees of GlaxoSmithKline.

Author information

Authors and Affiliations

  1. Department of Health Care Policy, Harvard Medical School, Boston, MA, USA

    Michael Chernew PhD

  2. Thomson Healthcare, Ann Arbor, MI, USA

    Teresa B. Gibson PhD

  3. Managed Markets Division, GlaxoSmithKline, Research Triangle Park, NC, USA

    Kristina Yu-Isenberg PhD, RPh

  4. Managed Markets Division, GlaxoSmithKline, Montvale, NJ, USA

    Michael C. Sokol MD, MS

  5. Departments of Internal Medicine and Health Management and Policy, Schools of Medicine and Public Health, University of Michigan, Ann Arbor, MI, USA

    Allison B. Rosen MD, ScD & A. Mark Fendrick MD

Authors
  1. Michael Chernew PhD
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  2. Teresa B. Gibson PhD
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  3. Kristina Yu-Isenberg PhD, RPh
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  4. Michael C. Sokol MD, MS
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  5. Allison B. Rosen MD, ScD
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  6. A. Mark Fendrick MD
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Corresponding author

Correspondence to Michael Chernew PhD.

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Chernew, M., Gibson, T.B., Yu-Isenberg, K. et al. Effects of Increased Patient Cost Sharing on Socioeconomic Disparities in Health Care. J GEN INTERN MED 23, 1131–1136 (2008). https://doi.org/10.1007/s11606-008-0614-0

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  • DOI: https://doi.org/10.1007/s11606-008-0614-0

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