Webpage Search and Identification
The Googleâ search engine was used to collate the first twenty webpage URLs for three individual searches for ‘COVID’, ‘COVID-19’, and ‘coronavirus’. When searching for information on the internet users typically will pick one of the first five search results, and will typically rephrase their search criteria instead of proceeding to the second page (or further)10, as a result we only included results from the first page of search engine results. The searches were conducted from geolocation search engine settings, in web-browser Google Chrome Version 85, to reflect the webpages found in Ireland, the United Kingdom, Canada and the United States. All searches were conducted on 17th April 2020. All previous search history and data caches were cleared before the first search, and between searches. Webpage results are tabulated in Appendix 1. Results were categorised by two researchers (AW and MC) independently based on source provenance of the webpage; ‘government and public health organisations’, ‘educational or scientific institution’, ‘digital media’ or ‘other’. A fifth category of ‘peer-reviewed journals/articles’ was included, but no webpage results fell into this category, and as such we have not included it in results. Source provenance for ‘government and public health organisations’ required that the webpage was supported, funded or hosted on a government, state, county or federal website platform (.gov.us, .gov.nl.ca, hse.ie, nhs.co.uk, as some examples), ‘educational or scientific institutions’ included sources such as Mayo Clinic, Medline, WebMD, etc., ‘digital media’ sources were webpages from news outlets, newspaper digital platforms etc., and ‘other’ captured the remaining webpages that fell out of these categories, similar to previous published categories in readability analyses11.
Readability Assessment Tools
Four scores were used to calculate readability of the webpages; the Gunning Fog Index (GFI), the Flesch Kincaid Index (FKG) Score and Flesch Reading Ease Score (FRES) and the Simple Measure of Gobbledygook (SMOG) Index. To ensure consistency and avoid human error the readability tests were done using an online readability calculator to provide FRES, FKG, GFI and SMOG scores12. All webpages were screened by the readability tool and hyperlinks, non-standard text, abbreviations and author names were not included in the analysis to prevent low-skewing of results.
The Flesch Reading Ease Score (FRES)
The FRES is a tool that indicates readability of English text on a 100-point scale. The FRES can be calculated using the following formula: [206.835 – (1.015x(total words÷total sentences)) – (84.6x(total syllables÷total words))]. The higher the score the greater the ease of comprehension, e.g. >90 scores indicate something that would easily be understood by a 10-11 year old. A recommended score between 60-70 represents a suitable readability level for most 13 year olds, which adequately captures most patient cohorts13.
The Flesch-Kincaid Grade Score
The Flesch-Kincaid Grade (FKG) Score is a readability test used extensively in educational settings, it gives a marker of readability with a weighting on syllables. It can be calculated with the following formula: 0.39 (total words/total sentences) + 11.8 (total syllables/total words) -15.59. The resulting number gives an estimated United States grade level equivalent. For universal accessibility and readability a suitable score is <8.
The Gunning Fox Index
The GFI tool is an English language tool measuring readability by estimating years of formal education needed to understand a text on the first time of reading. The GFI can be calculated using the following formula: 0.4x[(words÷sentences) + 100x(complex words÷ total words)]. A lower score indicates sample text that is more easily read. The GFI scale runs from 6-17; where 6 represents the reading level of an 11-12 year old, 12 is an 18 year old who has completed second level education, and 17 is a university level graduate13. Information requiring near universal readability should have a GFI <814.
The Simple Measure of Gobbledygook Index
The SMOG readability index estimates the number of years of formal education that a reader would need in order to read the material tested. The SMOG formula is: 3 + square root √ [number of polysyllabic words x (30 ÷ number of sentences)]. SMOG is only validated in the English language and is validated in healthcare information studies15. A suitable SMOG score for universal readability is 10.
Statistical Analysis
Descriptive statistics were calculated for SMOG, FRES, FKG and GFI scores. Shapiro-Wilk test determined parametric or non-parametric data distribution. Mean (SD) were used for normally distributed data, while median (range) were used for non-parametrically distributed data. Spearman’s correlations and Pearson’s correlations were used to assess non-parametric and parametric association between readability scores respectively. ANOVAs and Kruskall-Wallis tests were used to compare differences between the mean or median readability scores for univariate group analysis to determine differences between country, continent and source provenance. A 5% level of significance was used for all statistical tests. All statistical analysis was performed using GraphPad Prism software Version 8 (La Jolla, CA, USA, 2020), SPSS Statistics Version 26 (IBM, 2020) and Microsoft Office Excel Version 16 (USA, 2018).