Is There Any Research Evidence Beyond Surveys and Opinion Polls on Automatic Substitution of Biological Medicines? A Systematic Review.

BACKGROUND

Biosimilars are expected to decrease growing health care expenditures. Given that uptake of biosimilars has been modest, automatic substitution has been suggested to increase their use, but the practice is not yet allowed or implemented in many jurisdictions.

METHODS

A systematic review was performed by searching databases Scopus, Medline (Ovid), CINAHL, and Web of Science. Peer-reviewed, original studies written in English and published during the period January 1, 2006 to April 24, 2021 reporting any interventions, pilots or any other studies including experiences or perceptions of any relevant stakeholders on automatic substitution of biologics were included without limitation by setting or geography. The quality of the included studies were evaluated by pre-determined criteria.

RESULTS

Altogether, 27 studies fulfilled the inclusion criteria, of which 23 were surveys, and four semi-structured interviews reporting mainly stakeholders' perceptions on automatic substitution. Most of the studies (56%, 15/27) were from Europe. Studies were conducted among prescribers (n = 12), pharmacists (n = 5), patients (n = 4), payers (n = 1), and mixed stakeholders (n = 5). The primary objective of the majority (81%, 22/27) of the studies was to investigate some other biosimilar topic than automatic substitution. The reported perceptions of substitution were mainly negative. Studies evaluating risks, safety or effectiveness, or reporting real-life experiences of biologic substitution were lacking except one intervention and two prospective risk management studies. The overall quality of the studies was low to moderate, and the results were not generalizable due to convenience sampling not representing the populations of interest, and low response rates.

CONCLUSIONS

The current research evidence on the automatic substitution of biologics is scarce and of low to moderate quality, reflecting low stakeholder knowledge and their cautious attitude towards biosimilars. The safe and efficient implementation of automatic substitution requires well-designed practices, pilot studies, and evolving legislation.