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Does Prescription Drug Adherence Reduce Hospitalizations and Costs?

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  • William Encinosa
  • Didem Bernard
  • Avi Dor

Abstract

We estimate the impact of diabetic drug adherence on hospitalizations, ER visits, and hospital costs, using insurance claims from MarketScan® employer data. However, it is often difficult to measure the impact of drug adherence on hospitalizations since both adherence and hospitalizations may be correlated with unobservable patient severity. We control for such unobservables using propensity score methods and instrumental variables for adherence such as drug coinsurance levels and direct-to- consumer-advertising. We find a significant bias due to unobservable severity in that patients with more severe health are more apt to comply with medications. Thus, the relationship between adherence and hospitalization will be underestimated if one does not control for unobservable severity. Overall, we find that increasing diabetic drug adherence from 50% to 100% reduced the hospitalization rate by 23.3% (p=0.02) from 15% to 11.5%. ER visits are reduces by 46.2% (p=.04) from 17.3% to 9.3%. While such an increase in adherence increases diabetic drug spending by $776 a year per diabetic, the annual cost savings for averted hospitalizations are $886 per diabetic, a cost offset of $110 (p=0.02), or $1.14 per $1 spent on drugs.

Suggested Citation

  • William Encinosa & Didem Bernard & Avi Dor, 2010. "Does Prescription Drug Adherence Reduce Hospitalizations and Costs?," NBER Working Papers 15691, National Bureau of Economic Research, Inc.
  • Handle: RePEc:nbr:nberwo:15691
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    References listed on IDEAS

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    Cited by:

    1. Katherine Baicker & Sendhil Mullainathan & Joshua Schwartzstein, 2015. "Behavioral Hazard in Health Insurance," The Quarterly Journal of Economics, Oxford University Press, vol. 130(4), pages 1623-1667.
    2. Vincenzo Atella & Federico Belotti & Valentina Conti & Claudio Cricelli & Joanna Kopinska & Andrea Piano Mortari, 2016. "Modeling public health care expenditure using patient level data: Empirical evidence from Italy," CEIS Research Paper 367, Tor Vergata University, CEIS, revised 10 Feb 2016.
    3. Aurélie Côté-Sergent & Pierre-Carl Michaud, 2013. "L'aide aux personnes âgées avec incapacités et la consommation de médicaments au Québec," Cahiers de recherche 1316, CIRPEE.
    4. Gourzoulidis, George & Kourlaba, Georgia & Stafylas, Panagiotis & Giamouzis, Gregory & Parissis, John & Maniadakis, Nikolaos, 2017. "Association between copayment, medication adherence and outcomes in the management of patients with diabetes and heart failure," Health Policy, Elsevier, vol. 121(4), pages 363-377.
    5. Borrescio-Higa, Florencia, 2015. "Can Walmart make us healthier? Prescription drug prices and health care utilization," Journal of Health Economics, Elsevier, vol. 44(C), pages 37-53.

    More about this item

    JEL classification:

    • H51 - Public Economics - - National Government Expenditures and Related Policies - - - Government Expenditures and Health
    • I11 - Health, Education, and Welfare - - Health - - - Analysis of Health Care Markets

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