Background Directly observed treatment (DOT) has been the standard of care for tuberculosis since the early 1990s. In England DOT is targeted at those considered to be at high risk of poor adherence and clinically complex patients. We report the first randomised controlled trial of smartphone-enabled video observation of treatment (VOT) for active tuberculosis compared to DOT.

Methods Tuberculosis patients eligible for selective DOT in England were randomised to an offer of asynchronous VOT (daily remote observation using a smartphone app) or DOT (3 or 5 times weekly observation in community or clinic settings).

Results 58% of 226 randomised patients had a history of homelessness, drug use, imprisonment, alcohol or mental health problems. Of the 112 patients randomised to an offer of VOT, 70% had over 80% of scheduled observations completed over two months (the primary outcome measure) compared to 31% of 114 patients randomised to an offer of DOT (p<0.001). The effect was, in part, due to 51% of those randomised to DOT having less than one week of observation (compared to 10% of those randomised to VOT), and so not starting treatment with their allocated regimen. VOT patients sustained high observation levels throughout treatment, whereas this declined rapidly in DOT patients. We estimate that observation of a six month course of treatment with daily VOT cost £1645 per patient compared to £5700 for five times per week DOT.

Conclusions VOT is a more effective and cheaper approach to observation of tuberculosis treatment than clinic or community based DOT.