A comprehensive mixed-methods usability evaluation of COVID-19 home test kits: focusing on effectiveness, efficiency, and satisfaction.

This study evaluated COVID-19 home test kit usability focusing on effectiveness, efficiency, and satisfaction across diverse users and environments. Using a mixed-methods approach-including use analysis, user experience survey (n = 1045), and usability testing (n = 80) in South Korea-we identified a significant gap between high user satisfaction and actual performance. Despite positive satisfaction metrics (SUS score: 74.37 %), we observed concerns regarding effectiveness (29.9 % error rate) and efficiency (20 % unnecessary second kit use, 57.5 % repeated instruction references). The usability of home test kits was significantly influenced by age, education level, and prior experience, while the testing environment showed a less pronounced but still observable effect. Based on our findings, we propose design improvements to instructions, physical components of test kits, and instruction presentation. This research highlights the importance of usability in designing test kits that accommodate diverse populations, potentially improving public health outcomes and pandemic preparedness.