Cost-effectiveness of isoniazid chemoprevention in close contacts

The aim of the present study was to perform a cost-effectiveness analysis in young and middle-aged adults with latent tuberculosis (TB) infection in Germany. A Markov model simulated the progression of 20- and 40-yr-old close contacts of active TB cases over 20 yrs. Health and economic outcomes of isoniazid (INH) chemoprevention versus no intervention were compared. The analysis determined the incremental cost-effectiveness ratio in terms of cost per quality-adjusted life year and the difference between numbers of TB cases and of TB-related deaths. INH chemoprevention prevented 79% of expected TB cases in both age groups, and saved 9,482 and 9,142 in the lower and higher age groups, respectively, per case prevented. Quality-adjusted life expectancy was slightly extended by 8 days in the lower age group and 7 days in the higher age group, at a cost saving of 417 and 375, respectively, per person. Annual savings were 20,862 and 18,742 per 1,000 contacts, respectively. The number needed to be treated to prevent one TB case in the lower age group was 23 and 25 in the higher age group. The programme also prevented three TB-related deaths in the younger and two in the older cohort. The results are highly sensitive to treatment-cost assumptions. In conclusion, isoniazid chemoprevention in Germany is a highly cost-effective approach for reducing the burden of tuberculosis in recently converted young and middle-aged adults.