DOT entails a trained "observer" acceptable to both the patient and the health system being present to monitor treatment adherence as patients swallow anti-TB drugs. In the United States, DOT remains a cornerstone of TB control. While DOT represents the treatment standard, the implementation of DOT has been modified by some programs in an effort to reduce costs and conserve program resources. In the U.S., efforts recently have sought to utilize advances in communication technology to facilitate the implementation of DOT.