Generic dispensing rates for substitutable drugs prescribed by general practitioners compared with other private ambulatory specialists: A study based on a French national reimbursement database.

European Journal of General Practice 2024, VOL. 30, NO. 1, 2407600 https://doi.org/10.1080/13814788.2024.2407600 Research Article Generic dispensing rates for substitutable drugs prescribed by general practitioners compared with other private ambulatory specialists: A study based on a French national reimbursement database Hugo Figonia,b* , Sarah Roberta*, Kim Bonelloa, Gladys Ibaneza,c, Julie Chastanga,c† and Candice Estellatb† Department of General Practice, School of Medicine, Sorbonne University, Paris, France; bSorbonne Université, INSERM, Institut Pierre Louis d’Epidémiologie et de Santé Publique (IPLESP), équipe PEPITES, AP-HP, Hôpital Pitié Salpêtrière, Département de Santé Publique, Centre de Pharmacoépidémiologie (Cephepi), Unité de Recherche Clinique PSL-CFX, Paris, France; cSorbonne Université, INSERM, Institut Pierre Louis d’Epidémiologie et de santé Publique (IPLSEP), équipe de Recherche en Epidémiologie Sociale (ERES), Paris, France a KEY MESSAGES • 82% of substitutable drugs prescribed by French private general practitioners in 2019 were dispensed in generic form. • No other ambulatory specialty rated significantly higher than general practitioners. • Research is needed to study reasons for non-generic drug prescription in the context of legislative changes. ABSTRACT Background: The use of generic drugs is a way for healthcare systems to reduce costs, particularly in ambulatory care. Several studies suggest that the prescriber’s speciality is associated with the use of generic drugs, and that substitutable drugs prescribed by General Practitioners (GPs) are more often generic, but this association has never been studied in France. In the French legislative context, except in rare situations, all substitutable drugs prescribed should be dispensed in generic form. Objectives: Compare the generic drugs dispensing rate among substitutable drugs dispensed in community pharmacies prescribed by French private GPs with that of other private specialists, all other specialities combined (first objective) or each other speciality taken individually (second objective). Methods: We used a sample of an open available semi-aggregated database from the 2019 French health insurance system database. We compared with logistic regression models GPs to all other specialities combined, then GPs to the 19 other specialties taken individually, only on the substitutable drugs they prescribe in common. Results: In 2019, 53.4% of the drugs prescribed by French private ambulatory physicians were substitutable drugs, and 81.5% of them were dispensed in generic form. After adjustment, the generic dispensing rate for substitutable drugs was significantly higher for GPs than for other specialties (ORa 0.74 [IC95% 0.72–0.76]). Thirteen of the nineteen other specialities taken individually, such as endocrinologists (ORa 0.64 [IC95% 0.57–0.72]) and cardiologists (ORa 0.60 [0.56–0.63]) had significantly lower generic dispensing rates than GPs. No other speciality had a rate significantly higher than GPs. Conclusions: Substitutable drugs prescribed by French private GPs are more often dispensed in generic form than those from other private ambulatory specialties. To understand this result and optimise the use of generic drugs in outpatient settings, we need to study the different stages of drug use, from prescription by the physician to dispensing by the pharmacist and acceptance by the patient. ARTICLE HISTORY Received 12 December 2023 Revised 13 September 2024 Accepted 17 September 2024 KEYWORDS Drugs; generic; pharmacoepidemiology; database; primary health care; general practice CONTACT Hugo Figoni Department of General Practice, School of Medicine, Sorbonne University, 27 rue Chaligny, cedex 12, Paris 75571, France. * Co-first authors. † Co-last authors. Supplemental data for this article can be accessed online at https://doi.org/10.1080/13814788.2024.2407600. © 2024 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. The terms on which this article has been published allow the posting of the Accepted Manuscript in a repository by the author(s) or with their consent. 2 H. FIGONI ET AL. Introduction For several decades, World Health Organisation (WHO) has been recommending the deployment of policies to promote the development of and access to generic drugs [1]. Most of drugs on the WHO essential medicines list are off patent and available as generics [2]. They are offered at lower prices than brand name drugs, thus reducing costs for patients and the health system, particularly in primary care [3]. In this framework the European Union pharmaceutical policy aims to optimise drugs use and rationalise the cost of pharmaceuticals [4]. Market share of generic drugs differs across countries [5]. According to the data from the Organisation for Economic Cooperation and Development (OECD) in 2018, among the 14 countries surveyed, Switzerland, Italy and France were the countries with the lowest volume shares of generic drugs in the total pharmaceutical market with 20.8%, 26.8% and 29.9%, respectively. In contrast, Canada, Slovakia, and the Czech Republic had the highest market shares by volume with 76.0%, 64.5% and 63.3%, respectively [6]. Some of these variations can be explained by specificities of national markets related to regulatory structures and health systems, including differences in policies related to prescribing, substitution, reimbursement conditions and drug pricing [3]. Worldwide, studies conducted in countries with different generic drug policies, and few in France, have investigated factors associated with generic drugs use and have been combined in reviews [7–12]. Some of these studies suggested that generic drugs use were different across prescriber specialties [11,13,14]. For example, Federman et al. found in the United States in 2007 that patients over 66 with heart disease followed by a cardiologist were less likely to use generic drugs than those followed by a General Practitioner (GP) only [14]. French National Health Insurance provides a high level of reimbursement for drugs, from 15% to 65% and up to 100% for chronic diseases, which are classified as ‘long-term conditions’. In France since 1999, pharmacists can substitute drugs under some conditions, i.e. dispensing a generic drug instead of prescribed brand name [15]. Drugs that can be substituted are listed in the generic drug list, which includes brand name drug and associated generic drugs [16]. Consumers can oppose substitution but must advance payment before reimbursement. Since 2015, French physicians are obliged to include on the prescription the International Non-p (...truncated)