Figure 1. Schematic of asynchronous VDOT in a study assessing VDOT for monitoring tuberculosis treatment, 5 California health districts, 2015–2016. Patients use VDOT smartphone application to record a video of themselves ingesting their medications. After recording stops, the application encrypts the video and transfers it through a cellular or Wi-Fi connection to a server for storage and playback. On a routine basis, treatment monitors log into a secure website to view each video and document their observations. Missing videos or videos not showing complete dose ingestion trigger follow-up procedures to investigate missed doses and provide patient support as needed. VDOT, video directly observed therapy.