Adherence to changing from brand-name to generic atorvastatin in newly treated patients: A retrospective cohort study using health insurance claims

被引:6
作者
Mano Y. [1 ]
Fukushima S. [1 ]
Kuroda H. [1 ]
Ohshima H. [1 ]
Kato Y. [1 ]
Ohuchi K. [1 ]
Maezawa K. [1 ]
Momose Y. [1 ]
Ikeda S. [1 ]
Asahi M. [1 ]
机构
[1] International University of Health and Welfare, Department of Pharmaceutical Sciences, Otawara, Tochigi
关键词
Adherence; Atorvastatin; Claim database; Cohort study; Generic substitution; Persistence; Proportion of days covered;
D O I
10.1186/s40780-015-0013-8
中图分类号
学科分类号
摘要
Background: Effect of statin therapy has been reported to be associated with patient's adherence. Atorvastatin was available in Japan as a brand-name product beginning in 2000. The first atorvastatin generics were introduced in Japan in November 2011. The objective of this study was to analyze whether changing from a brand-name atorvastatin to a generic product would affect patient adherence. Methods: We conducted a retrospective cohort study that included adult patients who received newly prescribed brand-name atorvastatin between June 1, 2011 and May 31, 2012, using a health insurance claims database in Japan. Patients were classified by the presence or absence of changing to a generic during the 6 months from December 1, 2011 to May 31, 2012 (the index period). The first prescription date for the generic or brand product during the index period was defined as the index date. Adherence to therapy was assessed by the proportion of days covered (PDC) and persistence of treatment by time to discontinuation. Results: There were 135 patients changing to generic atorvastatin and 147 continuing with the brand-name product. There was no significant difference in decrease of PDC from pre- to post-index date between the changed cohort and continued cohort (-8.6% vs -10.3%, respectively; P = 0.443). After adjusting for baseline covariates, including adherence in pre-index date, no statistically significant differences were observed in the adjusted odds of adherence between the cohorts (adjusted odds ratio = 0.83, 95% confidence interval (CI) = 0.46-1.53). There was also no significant difference in persistence between two cohorts in the 180-day after post-index date. After analysis of a Cox proportional hazard regression model controlling for baseline covariates, including adherence in pre-index date, no statistically significant differences were observed for the hazard of non-persistence between the cohorts (adjusted hazard ratio = 0.96, 95% CI = 0.60-1.53). Conclusions: Changing from a brand-name atorvastatin to generic product did not affect adherence for patients newly treated with atorvastatin. © 2015 Mano et al.; licensee BioMed Central.
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  • [1] Dunne S., Shannon B., Dunne C., Cullen W., A review of the differences and similarities between generic drugs and their originator counterparts, including economic benefits associated with usage of generic medicines, using Ireland as a case study, BMC Pharmacol Toxicol, 14, (2013)
  • [2] (2014)
  • [3] Sander J.W., Ryvlin P., Stefan H., Booth D.R., Bauer J., Generic substitution of antiepileptic drugs, Expert Rev Neurother, 10, pp. 1887-1898, (2010)
  • [4] Himmel W., Simmenroth-Nayda A., Niebling W., Ledig T., Jansen R.D., Kochen M.M., Et al., What do primary care patients think about generic drugs?, Int J Clin Pharmacol Ther, 43, pp. 472-479, (2005)
  • [5] Dunne S., Shannon B., Dunne C., Cullen W., Patient perceptions of generic medicines: a mixed-methods study, Patient, 7, pp. 177-185, (2014)
  • [6] Shrank W.H., Liberman J.N., Fischer M.A., Girdish C., Brennan T.A., Choudhry N.K., Physician perceptions about generic drugs, Ann Pharmacother, 45, pp. 31-38, (2011)
  • [7] Sever P.S., Dahlof B., Poulter N.R., Wedel H., Beevers G., Caulfield M., Ostergren J., Et al., ASCOT investigators: Prevention of coronary and stroke events with atorvastatin in hypertensive patients who have average or lower-than-average cholesterol concentrations, in the Anglo-Scandinavian Cardiac Outcomes Trial--Lipid Lowering Arm (ASCOT-LLA): a multicentre randomised controlled tria, Lancet, 361, pp. 1149-1158, (2003)
  • [8] Arca M., Gaspardone A., Atorvastatin efficacy in the primary and secondary prevention of cardiovascular events, Drugs, 67, pp. 29-42, (2007)
  • [9] Rasmussen J.N., Chong A., Alter D.A., Relationship between adherence to evidence-based pharmacotherapy and long-term mortality after acute myocardial infarction, JAMA, 297, pp. 177-186, (2007)
  • [10] Shalev V., Chodick G., Silber H., Kokia E., Jan J., Heymann A.D., Continuation of statin treatment and all-cause mortality: a population-based cohort study, Arch Intern Med, 169, pp. 260-268, (2009)