EVALUATION OF TUBERCULOSIS-CONTROL POLICIES USING COMPUTER-SIMULATION

Objective.-To develop more effective methods to assess tuberculosis (T B) control strategies so we can meet national goals for the eliminatio n of TB in the United States. Design.-Using a semi-Markov model that d ivided the US population into 3 age groups and 18 clinical states base d on disease status and risk for TB and human immunodeficiency virus ( HIV) infection, we measured the effects of 5 changes in TB policy, int roduced singly and in combination: (1) increased coverage and (2) impr oved efficacy of preventive therapy, (3) increased coverage and (4) im proved efficacy of treatment, and (5) introduction of BCG vaccination. Results.-A BCG Vaccination program that reached 10% of eligible child ren and 1% or eligible adults each year would produce a 17% reduction in cases and an 11% decline in deaths over 10 years. Preventive therap y programs among the general population would have little effect on th e number of TB cases, but a program targeting HIV-infected patients wo uld reduce HIV-associated TB cases and deaths 14% to 20%. A 10% improv ement in the coverage and efficacy of both preventive therapy and trea tment, coupled with the BCG vaccination program, would lead to a 47% d ecline in TB cases and a 50% decline in TB deaths relative to baseline over 10 years. Conclusions.-Improvements in treatment coverage or eff ectiveness alone are unlikely to reach established national goals for the elimination of TB. These goals can be achieved through a combinati on of improvements in current programs with targeted preventive therap y and BCG vaccination programs.