The scope of the controlled clinical trial, illustrated by studies of pulmonary tuberculosis.

This report draws attention to the wide use of the controlled clinical trial in the study of tuberculosis in certain countries and centres and to the remarkable neglect of this method in the great majority of countries. Its versatility has been demonstrated by many studies: it has been used to study not only alternative combinations of drugs but also drug dosages, rhythms of administration, the duration of treatment with supplementary drugs or the total duration of treatment, and drug toxicity and its prevention. A particularly valuable use of the method is in the study of policies of therapy-e.g., treatment at home compared with treatment in a sanatorium; the inclusion of routine home visiting in the supervision of patients; the carrying out of pretreatment sensitivity tests as a basis for the selection of chemotherapeutic regimens; and treatment programmes based on short (6-month) intensive courses, as opposed to long-term (18-month) standard courses. It is concluded that well planned controlled clinical trials can be of great help to the epidemiologist and public health administrator as well as to the clinician.