Cost–benefit analysis of pre-entry tuberculosis screening for incoming migrants to Japan: a focus on Nepalese migrants

Nepalese students in Japan surged from under 1,000 in 2008 to over 29,000 by 2019, driven by Japan’s strategy of using student visas to fill unskilled labor gaps. This study examined the cost and benefit impact of the introduction of pre-entry tuberculosis (TB) screening policy, including testing and treatment for Japan and Nepal from 2014 to 2018. This study used anonymous data of TB statistics of diagnosis and treatment from the Nepal Demographic and Health Survey and from Japan’s Legal Affairs Bureau and Tuberculosis Surveillance Center. We used social cost–benefit analysis to examine the effect of the pre-entry TB screening policy on visas of Nepalese workers and students to Japan. Total cost, total benefit and net benefit for both countries were compared for the policy scenarios “With” and “Without”, using net present value (NPV). In order to address parameter differences for uncertainty, we conducted sensitivity analysis using the Monte Carlo simulation with secondary transmission rate. Between 2014 and 2018 in Japan, net present value (NPV) of Nepalese students increased from USD 1.9 million to USD 3.1 million; likewise, NPV of Nepalese workers grew from USD 1.1 million to USD 3.2 million. From the perspective of Japan, the increase in NPV was greater than zero, meaning that the implementation of the policy could produce a benefit for Japan regarding prevention of an increase in new TB cases. The total NPV was USD -51.6 million, as pre-entry screening and treatment costs are incurred by both emigrants and the national health system. Implementing a pre-entry TB screening policy for foreign migrants from high-burden countries such as Nepal could yield cost savings by reducing the incidence of newly diagnosed and potentially transmissible TB cases. Strong collaboration could ensure the follow-up and incentive for burden sharing of the implementation cost. Policy implementation of pre-entry TB screening in Japan was assessed by social value using cost benefit analysis on both Nepalese and Japanese perspectives. The policy effectiveness calculated the risks of TB incidence related to cost and benefit with transmission risks. The policy evaluation suggests that pre-entry TB screening would have prevented the increase in number of new TB cases in Japan, and would in turn have reduced TB healthcare costs and productivity loss.