A readability assessment of Plain Language Summaries and abstracts of Cochrane Systematic Reviews published during 2019

Article type
Authors
Meza N1, Perez-Bracchiglione J1, Franco J2, Garnham R3, Tapia-Benavente L3, Olguín-Sepúlveda P3, Urrútia G4, Madrid E1
1Interdisciplinary Centre for Health Studies (CIESAL), Cochrane Associate Centre, School of Medicine, Universidad de Valparaíso
2Research Departament, Cochrane Associate Centre, Instituto Universitario Hospital Italiano
3Cochrane Associate Centre, School of Medicine, Universidad de Valparaíso
4Iberoamerican Cochrane Centre, Biomedical Research Institute Sant Pau, CIBER Epidemiología y Salud Pública, Barcelona
Abstract
Background:
Plain Language Summaries (PLS) of Cochrane Systematic Reviews (CSR) must be written in clear and simple language to serve a relevant aim of knowledge translation, and must be accurately summarised in a succinct and readable style, as a way to deliver the results to a broad audience. Cochrane has approved standards for the elaboration of the message of PLS, and the review groups have an important role as well, since they are expected to ensure these aspects.
Some groups have reported that readability of PLS might be difficult even for medical students, and those who have assessed readability have shown controversial results, and . Moreover, the readability of PLS over abstracts has not been fully elucidated on CSR.

Objectives:
To analyse the readability of the PLS and abstracts of CSR of interventions published during 2019.

Methods:
We undertook a cross-sectional study, aiming to assess the readability of all PLS and abstracts of CSR of interventions published during 2019. We excluded protocols, withdrawn reviews, and non-intervention CSR (prognostic, diagnostic, etc.).

We retrieved all CSR from the Cochrane Database of Systematic Reviews published from January 1st to December 31st, 2019. We extracted the following data: Title, authors, country of affiliation of the corresponding author, Cochrane Review Group, and text of the PLS and abstract (including titles).

We assessed the readability of the abstracts and PLS using ‘Readability Formula’, as suggested by the MECIR Manual, in order to obtain the Statistical Measure Of Gobbledygook Index (SMOG), and other indices, which gives an estimate of the years of education needed to understand a text.

Results:
We analysed a total of 546 CSR. The resulting SMOG scores for abstracts were 11.32 (±1.55), while PLS scored 11.99 (±1.73), which was significantly different (p<0.001, meaning that PLS were less readable). 326 (59.7%) of these CSR had corresponding authors whose affiliations were from majority native English speaking countries (MNESC). There were no differences between the readability of PLS (p=0.05), according to whether corresponding authors’ affiliations were based in MNESC or not; and that was the same for abstracts (p=0.53). The differences in PLS and abstracts were also significant in subgroups of MNESC and non-MNESC main author.(see Table 1 of the attached figure).

Conclusions:
The abstracts and PLS of CSR published during 2019 have a readability for laypeople equivalent to 11th grade ( i.e.16 to 17 years old). PLS are significantly less readable than abstracts in all the CSR assessed, and we found no differences when the corresponding authors’ institutions are either from a MNESC or not. We found no differences among the readability of PLS or abstracts, when we compared MNESC with non-MNESC groups.

Patient or healthcare consumer involvement:
Patients and consumers will be able to take an active role in their health care as long as they have an adequate health literacy to understand the health information regarding their conditions.