Readability, linguistic characteristics and conclusiveness of Cochrane plain language summaries: a cross-sectional study

Article type
Authors
Banić A1, Fidahić M2, Šuto J3, Ščepanović R1, Vuka I1, Puljak L4, Buljan I5
1PhD candidate at Translational Research in Biomedicine, School of Medicine, University of Split, Split
2Faculty of Medicine, University of Tuzla, Tuzla
3Graduate Student at the School of Medicine, University of Split, Split
4Center for Evidence-Based Medicine and Healthcare, Catholic University of Croatia, Zagreb
5Department of Research in Biomedicine in Health and Cochrane Croatia, School of Medicine, University of Split, Split
Abstract
Background:
Cochrane is constantly trying to improve the dissemination of evidence in health to different populations. One of the most important formats, aimed at the lay population are Cochrane Plain Language Summaries (PLSs), which should be written in a simplified language, easily understandable and providing clear message for the consumer.
Objectives:
The aim of this study is to assess Cochrane PLSs; to which extent they are customized for lay persons, providing readable, comprehensible and conclusive message to consumers.
Methods:
The study analysed a large number of PLSs (N=4405) of Cochrane intervention reviews in English language collected up to February 2019 to assess the level of readability (SMOG - Simple Measure of Gobbledygook Readability Formula) and emotional tone. In addition to available Review Group, authors collected descriptive data: year of publishing, number of authors and available languages in which the PLS is provided. Finally, two independent authors assessed the conclusions of Cochrane PLSs and categorized the conclusions in one of the nine categories: “positive”, “positive inconclusive”, “no evidence”, “no opinion”, “negative”, “negative inconclusive”, “unclear”, “equal”, “equal inconclusive”.
Results:
Median number of words per summary was 330 (Interquartile range (IQR) 213-437), with high levels of analytical tone and low levels of emotional tone, which indicates indicate that PLSs are written in an objective style, but with low emotional engagement for the reader. Median number of years of education needed to read the PLSs was 14.9 (IQR 13.8 to 16.1), indicating that the person needs almost 15 years of education in order to read the content with ease. The most prevalent conclusiveness category was the “no opinion” category, indicating that the PLS did not provide the clarified answers about the effectiveness of the therapy, and the categories were similarly dispersed across Cochrane groups (Figure 1).
Conclusions:
PLSs are predominantly written in objective style, with low levels of emotional tone and relatively high readability score, which makes them difficult to read for lay population without medical education. Future analysis will focus on the comparison of linguistic characteristics between PLSs with different conclusiveness categories, with aim to determine whether the conclusion type is related with writing style. Most of the PLSs did not provide a clear opinion regarding the effects of analyzed intervention. Our results indicate that PLSs are not so plain, and that further effort is needed to write PLSs that will be better suited for lay audience.
Patient or healthcare consumer involvement:
Patients were not involved in this study.