User experiences of DiTA (dita.org.au): a database of studies of diagnostic test accuracy

Background: The DiTA database indexes primary studies and systematic reviews of the accuracy of diagnostic tests related to physical therapy; however, its usability has not been previously assessed. Objective: (i) To assess the usability (layout, navigation, functionality, content) of DiTA for typical users working within physical therapy; (ii) to report the volume of user interaction with DiTA. Methods: A Think Aloud usability testing protocol was employed with 25 participants during screenshare teleconference interviews while performing DiTA search tasks. Participants then completed the System Usability Scale (SUS) online. Participants’ comments and interpretations from transcribed interviews were coded into four usability categories. Anonymous data on website user behaviour since DiTA’s inception were collected. The main outcome measures were frequency of comments per category with interpretations made during interviews, and SUS usability scores. Results: Participants most often commented about content (49 % of total), typically with positive sentiment. Participants also frequently commented on DiTA’s functionality typically with negative sentiment. Misinterpretations during search tasks were commonly coded into the functionality category. The SUS score of 70.9 was above the usability benchmark for similar platforms. Participants thought they could learn to use DiTA quickly. Since its launch in 2019, DiTA has averaged 88 visits per day, accessed from almost every country in the world, with most users coming from Brazil. Conclusion: Typical users rated DiTA’s usability as above average, commenting frequently on its content and most often positively. DiTA's functionality was often misinterpreted during search tasks. Nevertheless, participants believed DiTA could be learnt quickly.