Social trust and regional variation in the adoption of biosimilars in Italy and Germany

Abstract

Introduction/Study Objectives: Adoption of biosimilars has fallen below projections, despite the vigorous implementation of economic incentives, thereby highlighting the importance of behavioural factors such as social trust. This paper analyses biosimilar adoption across provinces in Italy and Germany, which evince strong variation in social trust, and across nations in Europe. Methods: Data for 2020 biosimilar adoption for Italian provinces were obtained from the national pharmaceutical organization and for German states from the association of biosimilar manufacturers. Social trust was coded for Italy and Germany using historical metrics; political trust was coded using the Quality of Government Index (QGI). Multivariable methods were used to ascertain the association between adoption, social trust, political trust, and income per capita. Regressions also were conducted using data at the national level for 20 European nations. The study includes two biologicals for chronic immunological conditions, three biologicals for acute cancer treatments, and their 20 biosimilars. Results: Adoption of biosimilars was much lower in regions suffering from low social trust and low trust in government, respectively, with penetration falling below the national median in seven out of eight provinces in southern Italy and in all seven provinces in eastern Germany. Rates of adoption are 21.5 percentage points higher in northern than in southern Italy and 5.2 points higher in western than in eastern Germany, controlling for other relevant factors. Provinces with low values on the QGI had significantly lower adoption than provinces with high citizen trust in government. Conclusion: Economic incentives to promote adoption of biosimilars must ensure that the benefits accrue to the populations most affected, thereby enhancing social trust and cooperation.