Enhanced repeated measurement of psychological tasks and form questions via a web-based mobile app.

Traditional paper-and-pencil methods have limitations for data collection in occupational health research. Here, we introduce a new web-based version (Fatigue checker web-ver.) of an application designed to better facilitate survey management and communication with participants. The application operates on mobile web browsers and integrates with LINE, Japan's most popular messaging app, and contains customizable forms, psychological tasks such as the Psychomotor Vigilance Task (PVT), Flanker Task, and n-back Task. Daily schedule acquisition is achieved via a dedicated user interface. Cross-correlation analysis showed fair synchronization between the app and gold-standard PVT equipment, indicating the app's reliability in measuring reaction times. Specifically, the analysis revealed significant cross-correlation for mean reaction time, median reaction time, mean reciprocal reaction time, and number of lapses, which indicates that the app can reliably measure fatigue and alertness levels. Since its release, the app has been successfully employed collecting high-quality data in six projects involving 571 participants. Despite minor issues, the app significantly improves the efficiency and accuracy of remote surveys, offering valuable insights into workers' health and safety. It also enables occupational health and safety specialists to monitor workers and workplaces from a broader perspective than traditional methods. The public version of the app also enables every worker to monitor their own occupational health and safety status. Insights from repeated self-checking of fatigue will promote better working conditions and environments.