Web-based Stroke Calculators in Clinical Decision Support: a Retrospective Analysis of Usage Patterns (Preprint)
BACKGROUND Clinical scores are frequently used in the diagnosis and management of stroke and cerebrovascular disease. While medical calculators are increasingly important clinical decision support tools, uptake and usage of commonly used medical calculators for cerebrovascular disease remain poorly characterized. OBJECTIVE To describe usage patterns in frequently used stroke-related medical calculators from a Web-based clinical decision support system. METHODS We conducted a retrospective study of calculators from MDCalc, a web-based medical calculator platform based in the United States. We analyzed metadata tags from MDCalc’s usage data to identify all calculators related to stroke. Using relative pageviews as a measure of calculator usage, we determined the 5 most frequently used stroke-related calculators between January 2016 and December 2018. For all 5 calculators, we determined cumulative and quarterly usage, mode of access (e.g., app or Web browser), as well as US geographic and international distributions in usage. We compared cumulative usage in the 2016-2018 period to usage from January 2011 to December 2015. RESULTS Over the study period, we identified 454 MDCalc calculators, of which 48 (10.6%) were related to stroke. Of these, the 5 most frequently used calculators were the CHA2DS2-VASc Score for Atrial Fibrillation Stroke Risk calculator (5.5% and 32% of total and stroke-related pageviews, respectively) the Mean Arterial Pressure (MAP) calculator (2.4%, 14.0%), the HAS-BLED Score for Major Bleeding Risk (1.9%, 11.4%), the National Institutes of Health Stroke Scale Score (NIHSS) calculator (1.7%, 10.1%), and the CHADS2 Score for Atrial Fibrillation Stroke Risk calculator (1.4%, 8.1%). Web browser was the most common mode of access, accounting for 82.7% to 91.2% of individual stroke calculator pageviews. Access originated most frequently from the most populated regions within the United States. Internationally, usage originated mostly from English-language countries. The NIHSS score calculator demonstrated the greatest increase in pageviews (238.1%) between the first and last quarter of the study period. CONCLUSIONS The most frequently used stroke calculators were for the CHA2DS2-VASc, MAP, HAS-BLED, NIHSS, and CHADS2. These were mainly accessed by Web browser, from English-speaking countries, and from highly populated areas. Further studies should investigate barriers to stroke calculator adoption and the effect of calculator usage on the application of best practices in cerebrovascular disease.