Refill Adherence in Relation to Substitution and the Use of Multiple Medications: A Nationwide Population Based Study on New ACE-Inhibitor Users

Abstract

ObjectiveGeneric substitution has contributed to economic savings but switching products may affect patient adherence, particularly among those using multiple medications. The aim was to analyse if use of multiple medications influenced the association between switching products and refill adherence to angiotensin-converting-enzyme (ACE) inhibitors in Sweden.Study Design and SettingNew users of ACE-inhibitors, starting between 1 July 2006 and 30 June 2007, were identified in the Swedish Prescribed Drug Register. Refill adherence was assessed using the continuous measure of medication acquisition (CMA) and analysed with linear regression and analysis of covariance.ResultsThe study population included 42735 individuals whereof 51.2% were exposed to switching ACE-inhibitor and 39.6% used multiple medications. Refill adherence was higher among those exposed to switching products than those not, but did not vary depending on the use of multiple medications or among those not. Refill adherence varied with age, educational level, household income, country of birth, previous hospitalisation and previous cardiovascular diagnosis.ConclusionThe results indicate a positive association between refill adherence and switching products, mainly due to generic substitution, among new users of ACE-inhibitors in Sweden. This association was independent of use of multiple medications.

A VOSviewer-Based Bibliometric Analysis of Prescription Refills

“…Sundell, Jonsson, Lesen, and Mardby have formed a group of authors with close cooperation, and they have been leaders in the research field. Their collaborative research focused on the comparison of different drug supplementation methods and the effects of drug substitution on the effectiveness of prescription refills (29)(30)(31). Meanwhile, according to the number of publications, citations, H-index, and other indicators, the Journal of the American Pharmacists Association, Pharmacoepidemiology and Drug Safety, British Medical Journal, and other journals were recognized as popular journals in the field of prescription refills.…”