DETERMINATION OF THE COST-EFFECTIVENESS OF A TUBERCULOSIS PREVENTION PROGRAM ALONG THE U.S. / MEXICO BORDER USING MARKOV PROCESS MODELING WITHIN A PREVENTION EFFECTIVENESS FRAMEWORK

OBJECTIVE: A prevention effectiveness analysis framework was used to estimate the cost-effectiveness of a tuberculosis prevention program compared to no program along the U.S./Mexico border. The prevention program used prophylactic isoniazid therapy in patients who tested positive for tuberculosis infection. This analysis evaluated the cost-effectiveness of the tuberculosis prevention from the county government perspective and was modeled over two time periods, 5 and 15 years post preventive therapy initiation. METHODS: The outcome of interest, cases of active tuberculosis averted, was calculated through a Monte Carlo simulated Markov process model. Costs were calculated using hospital discharge and actual tuberculosis prevention and active treatment program data. Average and incremental cost-effectiveness ratios were calculated for the tuberculosis prevention program scenario. Cost-effectiveness ratios were calculated separately with the inclusion or exclusion of the tuberculosis contagion costs. RESULTS: The results indicate that the tuberculosis prevention program provides cost-savings to the county. Baseline incremental cost-effectiveness ratios, for the 5 and 15 year analyses, demonstrated substantial cost savings (-$1,023 and -$4,971 per case adverted, respectively). Sensitivity analyses were performed across key transitional probabilities and discount rates. Results of sensitivity analyses indicate that as the rate of hospitalization for tuberculosis decreased and compliance with the preventive therapy decreased, cost effectiveness ratios increased to $2,015 and $ 877 per case averted, respectively, for the 5 year preventive treatment scenario. However, when the tuberculosis contagion consequences of not having the tuberculosis prevention program were considered; the cost-effectiveness and cost-savings were once again realized. CONCLUSION: The results indicate that rather than incurring costs to avert active tuberculosis cases, having the tuberculosis prevention program results in cost-savings.