Swedish patients’ trust in the bioequivalence of interchangeable generics. What factors are important for low trust?

BACKGROUND: Generic substitution (GS), is a cost-containment strategy meant to contain pharmaceutical expenditure without compromising health objectives. In order to shape GS into a policy that is both efficient and safe it is crucial to understand which factors are most important for patients’ trust in GS. OBJECTIVE: To assess Swedish patients’ level of trust in the bioequivalence of cheap and expensive generic medicines, and the association between trust and various factors. METHODS: A cross-sectional study was conducted. Questionnaires were handed out at 12 community pharmacies in Sweden, selected through stratified sampling, between March and April 2015. The questionnaire included seven socio-demographic questions in addition to 18 items divided into three sections: the ‘views on generic medicine’-scale, information on and prior experiences of GS, financial aspects and change of color/name. Odds Ratios (ORs) were estimated applying adjusted logistic regression analyses with trust in the bioequivalence of generic medicines used as outcome variable and various factors as predictors. RESULTS: A total of 719 patients participated (response rate 85.7%). The results show that 70.7% of the respondents’ trust that cheap and expensive interchangeable generic medicines are equal. Of the respondents 36.0% considered the change in appearance and 40.8% the change in names to complicate adherence. Lower trust in the bioequivalence of generic medicines were associated with being female (aOR=1.82, 95%CI 1.20:2.75, p<0.01), patients perceiving that changes in product name and appearance make adherence more complicated (aOR=2.18, 95%CI 1.48:3.19, p<0.001), disagreeing in that GS saves money for me (the customer) (aOR=2.68, 95%CI 1.58:4.55, p<0.001) or that GS saves money for society (aOR=3.21, 95%CI 1.46:7.08, p<0.01). CONCLUSIONS: Seven out of ten respondents had trust in the bioequivalence of generic medicines, and one in three considered GS to complicate adherence. Four factors were associated with lower trust in GS, i.e. female gender, agreeing that changes in product name and appearance complicates adherence, disagreeing in that GS saves money for me or disagreeing in that GS saves money for the society. Low trust in GS needs to be addressed, not least in the communication between health professionals and patients.