Simplification of medical texts: strategies and evaluation for COVID-19 and Flu vaccines package leaflets.

The specialised language is a variety of natural language derived from a field of knowledge and a community of experts who are part of a small number of speakers who know the specific characteristics of that language and need it to communicate in that specific field. What characterises specialised language is a specific vocabulary and the particular morphosyntactic and textual features. Moreover, concerning the textual features and the register used in this kind of language, it can be noted that a specialised text appears very clear, objective, unambiguous, brief and it does not contain emotional aspects because it is required to have a neutral approach. Usually, specialised languages are called Language for Specific Purpose (LSP) to designate the language of physics, medicine, economics and law. However, another important element concerning LSP is the monoreferentiality, in which one concept is related to one term that is specific and could not be common to everyone. For this reason, LSPs, and the terminology associated with it, are two of the main issues that interfere with the understandability of documents concerning a specific sector. This is the case of medical documents that are difficult in terms of readability for people with a basic knowledge of medicine. Readability is the ease with which a common reader can understand a text. Generally, the readability depends on its presentation such as the layout, the font size, the character spacing and line length and its content concerning the complexity of the vocabulary and the syntax. Medical language has a difficult structure because of its sentences which commonly contain nominalization and a lot of Latin and Greek-derived terms which are uncommon to the general language. This is the cause of the low readability of medical documents especially the package leaflets. During COVID-19 pandemic the vaccine leaflets have been in the centre of the attention because they were the only source of information concerning these new vaccines unknown to most of the people. This study aims to simplify the language used in package leaflets and the summary of the characteristics of COVID-19 and Flu vaccines and to extract the difficult terminology which is supposed to be difficult to understand in terms of readability. This kind of analysis allows to discover if the readability of package leaflets, in Italian and in English, can be improved by simplifying the terms that are considered highly medical. The measurement of the readability ease is examined through some of the most important readability formulas such as the Flesch-Kincaid readability test, the Gunning fog formula, the SMOG formula, the Coleman-Liau Readability Index and the Automated Readability Index, while the Italian one involved the use of the Flesch-Vacca Index, the Gulpease Index and the READ-IT tool. This work provides a simplification only on the lexical level, since the sentences in this kind of document are very brief; nevertheless, every term is simplified by searching the exact synonym which can be used in the general language or by explaining, through periphrasis, the meaning of the specific term. What emerged from the study is that not every term can be simplified, and it has to be as in the original text to avoid misinformation, for this reason it is challenging to improve the readability because some terms could give a low readability score.