Fig. 1

Decision Tree Model Comparing a Screening Program for Nonimmigrant Visa Applicants to No Screening Notes: Decision model does not display all nodes. Each cohort proceeds through the screening and no-screening arms of the model. PHD: public health department, TB: tuberculosis, NIV- non-immigrant visa. For the no-screening arm, all cases are diagnosed passively and treated in the United States. All costs accrue in the United States. For the screening arm, costs accrue in applicants’ home countries and in the United States. Costs are incurred for the panel physician medical exams and diagnosis and treatment as necessary. ¹The probability that an applicant has signs and symptoms of TB is based on the country-specific immigrant rate multiplied by a country-specific correction factor for applying immigrant data to our hypothetical populations. ²The number of active TB cases among NIV candidates from India and Mexico is the cohort size multiplied by the fraction with clinical findings suggestive of TB and by the fraction diagnosed with active TB given signs and symptoms. This group of applicants with active TB will not be able to enter the United States until they complete treatment. Among these, the probability that they are treated by panel physicians is applied to determine cost of treatment to the patient via panel physician (opportunity and treatment costs) and to the national government (treatment costs for those treated outside the panel physician). Recruitment and visa costs are incurred by U.S.-based H-1B employers when applicants are treated outside the panel physician site. ³The total number of active TB cases in each cohort is the sum of the prevalent cases and incident cases. ⁴Among those with clinical signs or symptoms suggestive of TB, 78.6% of Mexicans and Indians follow up with PHDs after arrival in the United States. Among Class B1 arrivals who did not have active TB, 2.6% of Indians and 0.6% of Mexicans develop incident cases of TB and incur treatment costs in the United States. Such cases will be detected actively if they follow up with a PHD or passively if they do not