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Effect of copayment policies on initial medication non-adherence according to income: a population-based study
  1. Ignacio Aznar-Lou1,2,
  2. Anton Pottegård3,
  3. Ana Fernández2,4,
  4. María Teresa Peñarrubia-María2,5,
  5. Antoni Serrano-Blanco2,6,
  6. Ramón Sabés-Figuera2,7,
  7. Montserrat Gil-Girbau1,8,
  8. Marta Fajó-Pascual9,
  9. Patricia Moreno-Peral10,11,
  10. Maria Rubio-Valera1,2,12
  1. 1 Research and Development Unit, Institut de Recerca Sant Joan de Déu, Barcelona, Catalonia, Spain
  2. 2 Centro de Investigacion Biomedica en Red de Epidemiologia y Salud Publica, Barcelona, Catalunya, Spain
  3. 3 Department of Clinical Pharmacology, University of Southern Denmark, Odense, Denmark
  4. 4 Service of Community Health, Public Health Agency of Barcelona, Barcelona, Catalonia, Spain
  5. 5 Institut Català de la Salut, Barcelona, Catalunya, Spain
  6. 6 Research and Development Unit, Parc Sanitari Sant Joan de Déu, Barcelona, Catalonia, Spain
  7. 7 Faculty of Economics and Business Science, Universitat Pompeu Fabra, Barcelona, Catalonia, Spain
  8. 8 Primary Care Prevention and Health Promotion Research Network, Barcelona, Catalonia, Spain
  9. 9 Faculty of Health and Sport Sciences, University of Zaragoza, Huesca, Spain
  10. 10 Distrito de Atención Primaria Málaga-Guadalhorce, Málaga, Spain
  11. 11 IBIMA, Málaga, Spain
  12. 12 School of Pharmacy, University of Barcelona, Barcelona, Catalonia, Spain
  1. Correspondence to Dr Maria Rubio-Valera, Research and Development Unit, Institut de Recerca Sant Joan de Déu, Sant Boi de Llobregat, Barcelona, Spain; mrubio{at}


Objective Copayment policies aim to reduce the burden of medication expenditure but may affect adherence and generate inequities in access to healthcare. The objective was to evaluate the impact of two copayment measures on initial medication non-adherence (IMNA) in several medication groups and by income level.

Design A population-based study was conducted using real-world evidence.

Setting Primary care in Catalonia (Spain) where two separate copayment measures (fixed copayment and coinsurance) were introduced between 2011 and 2013.

Participant Every patient with a new prescription issued between 2011 and 2014 (3 million patients and 10 million prescriptions).

Outcomes IMNA was estimated throughout dispensing and invoicing information. Changes in IMNA prevalence after the introduction of copayment policies (immediate level change and trend changes) were estimated through segmented logistic regression. The regression models were stratified by economic status and medication groups.

Results Before changes to copayment policies, IMNA prevalence remained stable. The introduction of a fixed copayment was followed by a statistically significant increase in IMNA in poor population, low/middle-income pensioners and low-income non-pensioners (OR from 1.047 to 1.370). In high-income populations, there was a large statistically non-significant increase. IMNA decreased in the low-income population after suspension of the fixed copayment and the introduction of a coinsurance policy that granted this population free access to medications (OR=0.676). Penicillins were least affected while analgesics were affected to the greatest extent. IMNA to medications for chronic conditions increased in low/middle-income pensioners.

Conclusion Even nominal charge fixed copayment may generate inequities in access to health services. An anticipation effect and expenses associated with IMNA may have generated short-term costs. A reduction in copayment can protect from non-adherence and have positive, long-term effects. Copayment scenarios could have considerable long-term consequences for health and costs due to increased IMNA in medication for chronic physical conditions.

  • health policy
  • primary care
  • pharmacoepidemiology

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  • Contributors IAL and MRV designed the original study. IAL and MRV designed and conducted the analysis strategy. IAL, with the help of all authors, wrote the manuscript. All authors contributed to editing and approved the final version of the manuscript. MRV had full access to all data in the study and made the final decision to submit for publication.

  • Funding This work is supported by the Instituto de Salud Carlos III, Spanish Health Ministry (grant number: PI14/00052) and the Sociedad Económica Barcelonesa de Amigos del País.

  • Disclaimer Those funding the study had no role in study design, data analysis, data interpretation or writing of the report.

  • Competing interests None declared.

  • Patient consent Not required.

  • Ethics approval The study obtained approval from the Fundació Sant Joan de Déu Ethics Committee (PIC-111-14).

  • Provenance and peer review Not commissioned; externally peer reviewed.

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