# An Analysis of the Readability of Public-Facing Information Relating to Prevention of Infectious Diseases by Vaccination

## TL;DR

This study finds that public vaccine information is hard to read and suggests ways to improve it for better health literacy and vaccine uptake.

## Contribution

The study evaluates readability of vaccine-related public materials and provides specific recommendations for improvement.

## Key findings

- Most vaccine-related information fails to meet readability targets across all metrics.
- Plain language summaries improve readability but still fall short of recommended standards.
- Using readability tools and simpler language can enhance public understanding of vaccination materials.

## Abstract

The readability of public-facing vaccine-related information is an important aspect of health literacy particularly regarding vaccine uptake. The aims of this study were to analyse the readability of such written literature and to provide recommendations, for improvement.

Readability of vaccine-related information (ntotal = 240) from publicly available sources (n = 20 per category), including PubMed Abstracts, Expert Review of Vaccines (ERV) and Cochrane Reviews (CR), paired plain language and scientific abstracts, public health materials, clinical trial summaries and vaccine patient information leaflets, were assessed using the Flesch Reading Ease (FRE), Flesch-Kincaid Grade Level (FKGL), SMOG and Gunning Fog readability metrics using the readability software tool readable.com.

Vaccine-related information for all sources had poor readability across all readability metrics with 90.8% and 94.6% not reaching the target FKGL (≤8) (mean 12 ± 3.2 sd) and FRE (≥60) (mean 34 ± 17 sd). Plain language summaries had improved readability, but did not reach reference targets. Scientific abstract and plain language scores for the CR were FRE (mean 25 ± 7.2 sd; median 25) versus (mean 37 ± 8.6 sd; median 36) p < 0.0001), respectively and for ERV FRE the scientific abstract (mean 18 ± 11 sd; median 17) versus the plain language score (mean 26 ± 11 sd; median 28) p = 0.002), respectively, indicating an improvement in readability scores for plain language summaries but again not reaching reference targets.

The readability of public-facing vaccination materials is currently not optimum. The readability can be improved through the employment of readability calculators and ensuring, where possible, the use of mono-syllable words and less than fourteen words per sentence. The preparation of public-facing materials with improved readability scores will help aid in the promotion of health literacy and in turn promote vaccination uptake.