Package Leaflets for EU Biosimilars May Negatively Impact Adherence, Study Says

The package leaflet provided to a patient with any drug product includes crucial information about a given therapy that can increase adherence and appropriate use of the product. To help make these leaflets as useful as possible for patients, in 2009, the European Commission published a new guideline on the readability of these labels with the aim of making them easier for patients to understand.

A study newly published in BMJ Open sought to assess the readability of the package leaflets of biosimilars that are currently available in the EU market, and found that the leaflets for these drugs may not fulfill the role for which they were designed.

The cross-sectional analytical study included the 35 English-language package leaflets available online for biosimilars authorized for sale in the European Union as of August 2017. The products included hormones, insulins, granulocyte colony-stimulating factor (G-CSF) therapies, erythropoietins, low—molecular weight heparins, and monoclonal antibodies.

The investigators used the Flesch Index (which indicates how easy a text is to read) and the Flesch-Kincaid Index (which indicates a grade level needed to read a given text) to assess the readability of the leaflets.

They found that biosimilars’ leaflets were longer than those of reference biologics and, according to the Flesch Index, none of the leaflets was easy to understand, and all of them were more difficult to read than is recommended for health-related texts. There were significant differences between the sections of the leaflets in terms of length, with “possible side effects” containing the most text and “how to store” containing the least text. Readability of the sections also differed, with the “annex” of the labels (which generally contains information on how to handle the administration device) being the easiest to understand and “what [the product] is and what it is used for” being the hardest to understand.

Among the various types of biosimilars considered, anti—tumor necrosis factor (anti-TNF) therapies had the longest leaflets, while G-CSFs had the shortest. In terms of readability, heparins had the easiest leaflets to understand, while anti-TNFs had the hardest leaflets to understand.

“Excessive information in the package leaflets does not meet the requirements of patients,” write the authors, adding that “This becomes more important for biosimilars, the majority of which are prescribed in the treatment of serious diseases, such as cancer, as patients suffering from these conditions may experience a high degree of anxiety from the moment they receive the diagnosis.” A lack of readability, they say, could discourage patients from reading these inserts, or alarm patients who do read them, leading to reduced adherence.

In order to make these documents more likely to fulfill the function for which they are intended, readability tests should be applied to the leaflets prior to publication, say the authors.

Reference

Piñero-López MA, Figueiredo-Escribá C, Modamio P, Lastra CF, Mariño EL. Readability assessment of package leaflets of biosimilars. BMJ Open. 2019;9: e024837. doi: 10.1136/ bmjopen-2018-024837.