Assessing the economic impact of Rx-to-OTC switches: systematic review and guidelines for future development

Abstract

Introduction:

Switching drugs from prescription to non-prescription status (Rx-to-OTC) presents a unique set of challenges and opportunities to policy-makers and the industry in terms of managing health outcomes, pharmaceutical spending, and steering of consumer choices of therapy. Decision-analytic models are used to address uncertainty and produce reasonable estimates of the economic impact of switches for payers. This article presents a critical literature review of existing models which assess the economic impact of Rx-to-OTC switches, and provides guidelines in which future economic evaluations of Rx-to-OTC switches could be improved.

Methods:

A comprehensive search strategy was implemented in Medline and Embase, to retrieve published economic evaluations on Rx-to-OTC switches from 1995–2010. The research digest of the International Society of Pharmacoeconomics and Outcomes Research (ISPOR) was reviewed for potentially relevant abstracts for the past 3 years. Each model used was critically evaluated in terms of structure, relevance of inputs, methodology used, and robustness of results.

Results:

Worldwide, the economic impact of Rx-to-OTC switches has only been evaluated in a total of 12 peer-reviewed publications. Ten out of 12 studies were US-based, and two European-based. The models covered various disease categories, including allergy, hypercholesterolemia, gastroenterology, contraception, pulmonology, and virology. Seventy-five per cent of the models predicted cost savings for payers and patients. Limitations of the models mainly included use of strong assumptions and non-inclusion of specific populations due to lack of data. Guidelines were developed to help future model development. They cover structural issues on decision context, health states, and clinical outcomes, and other considerations for model specifications.

Conclusions:

Although reviewed studies lacked quality, this review of economic evidence of Rx-to-OTC switches suggests that switches may produce cost savings to public and private payers. This is especially important in light of the trend towards more switches.

Keywords::

• Prescription
• OTC
• Rx-to-OTC switch
• Policy

Transparency

Declaration of funding

This article was funded by Sanofi.

Declaration of financial/other relationships

Aurélie Millier and Slim Karray are employees from Creativ-Ceutical which received funding from Sanofi to develop this review. Joshua Cohen and Mondher Toumi have no relevant financial or other relationships to disclose. JME Peer Reviewers on this manuscript have no relevant relationships to disclose.

Acknowledgements

No writing assistance is to be declared in the preparation of this manuscript.

Previous presentation

A summary of this research was presented at the ISPOR 14th Annual European Congress, held in Madrid, Spain, 5–8 November 2011, Poster Code: PHP31.