International Journal of Public Health

, Volume 59, Issue 2, pp 329–339 | Cite as

The impact of cost-sharing schemes on drug compliance in Italy: evidence based on quantile regression

  • Vincenzo Atella
  • Joanna Aleksandra KopinskaEmail author
Original Article



In this article we investigate the causal effect of cost-sharing schemes on compliance with statins in a quantile regression framework.


We use the health search CSD-LPD data, a longitudinal observational dataset containing computer-based patient records collected by Italian general practitioners. We exploit a series of natural experiments referring to several introductions of co-payment schemes in some of the Italian regions between 2000 and 2009. We adopt an extended difference-in-differences approach to provide quantile estimates of the impact of co-payments on compliance.


We find that (i) introduction of co-payments hurts residents of regions with worse quality and provision of health care; (ii) within these regions, co-payments were particularly harmful for high compliers; (iii) gender, clinical history and geographic residence are important determinants of compliance among poor compliers; (iv) compliance decreases with the potency and dosage of statins, particularly for poor compliers.


In the presence of inefficient health-care provision, co-payments are harmful for drug compliance, and this is especially true for patients who are originally good compliers.


Compliance Cost sharing Co-payments Quantile regression Difference-in-differences Statins Cholesterol 

Supplementary material

38_2013_528_MOESM1_ESM.docx (89 kb)
Supplementary material 1 (DOCX 88 kb)
38_2013_528_MOESM2_ESM.tiff (4.8 mb)
Supplementary material 2 (TIFF 4921 kb) Timing of co-payment introductions in Italian regions (2002-2009)


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Copyright information

© Swiss School of Public Health 2013

Authors and Affiliations

  1. 1.Department of Economics and FinanceUniversity of Rome Tor Vergata, CHP PCOR Stanford UniversityRomeItaly
  2. 2.CEIS Tor VergataUniversity of Rome Tor VergataRomeItaly

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