Digital Impact Factor: A Quality Index for Educational Blogs and Podcasts in Emergency Medicine and Critical Care

Given the popularity of educational blogs and podcasts in medicine, learners and educators need tools to identify trusted and impactful sites. The Social Media Index was a multi-sourced formula to rank the effect of emergency medicine and critical care blogs. In 2022, a key data point for the Social Media Index became unavailable. This bibliometric study aimed to develop a new measure, the Digital Impact Factor, as a replacement.

The Digital Impact Factor incorporated modern measures of website authority and reach. This formula was applied to a cross-sectional study of active emergency medicine and critical care blogs and podcasts. For each website, we generated a Digital Impact Factor score based on Ahrefs Domain Rating and the follower count of the websites' pages from 8 social media platforms. A series of Spearman correlations provided evidence of association by comparing a rank-ordered list to rank lists derived from the Social Media Index over the last 5 years. The Bland-Altman analysis assessed for agreement.

The authors identified 88 relevant websites with a median Ahrefs Domain Rating of 28 (range 0 to 71, maximum 100) and total social media followership count across 8 platforms of 1,828,557. The Domain Rating and individual social media followership scores were normalized based on the highest recorded values to yield the Digital Impact Factor (median 4.57; range 0.02 to 9.50, maximum 10). The correlation between the 2022 Digital Impact Factor and the 2021 Social Media Index was 0.94 (95% confidence interval 0.89 to 0.97; p<.001; n=41 rankings correlated), suggesting that they measure similar constructs. The Bland-Altman plot also demonstrated fair agreement between the 2 scores.

The Digital Impact Factor is a measure of the relative effect of educational blogs and podcasts within emergency medicine and critical care.