Every doctor knows that it is often difficult to persuade patients to complete a course of treatment and not to leave off as soon as they feel better. This is particularly significant with antibiotics, in which stopping too soon has led to drug-resistant strains of disease. The problems are more acute when the patient is suffering from tuberculosis, which requires drugs to be taken for at least six months and in which the immediate symptoms can disappear quite quickly. A system has been developed, originally applied to uncooperative drug-takers in the US, in which health workers supervise the patient and ensure that the drugs are actually taken day by day. This is known by the cumbersome name directly-observed treatment (short-course), which is commonly and unsurprisingly abbreviated to DOTS. The term was in the news in March 1997 because the World Health Organisation seemed to be claiming that the use of this technique could bring the world-wide epidemic of TB under control within a decade, a claim regarded as preposterous by many experts.