Evaluation of tuberculosis control programs: some national trends.

Increasing numbers of tuberculosis control programs compile information about the number, location, bacteriologic status, and chemotherapy status of tuberculosis patients within their jurisdiction. Reports from these programs show that during the 1970s the prevalence of patients requiring supervision decreased three times faster than the incidence of tuberculosis; this decline occurred because low relapse rates among patients who had received adequate therapy allowed the recommended duration of follow-up after completion of therapy to diminish from lifetime to none. The prevalence of patients hospitalized for tuberculosis decreased four times faster than the incidence of tuberculosis because the duration of hospitalization decreased from many months to a few weeks and because a small proportion of patients were hospitalized. Future declines in these two program aspects are expected to be much smaller and should parallel the decline in morbidity more closely. Other measures of program performance have shown a less favorable trend and suggest an impeded flow of information to the health department from other persons or agencies involved in the care of tuberculosis.