Background: Tuberculosis (TB) patients crossing borders pose a serious challenge to global TB control efforts. The objectives of our study were firstly, to evaluate the trend and size of foreign-born pulmonary TB patients, who had been notified and initiated treatment in Japan but have transferred out of the country while still on treatment; and secondly, to conduct a detailed analysis of these patients and identify possible risk factors for international transfer-out, and discuss policy implications for a cross-border patient referral system for foreign-born TB patients in Japan. Methods: We conducted a cross-sectional study whereby aggregated cohort data of pulmonary TB cases newly notified to the Japan TB Surveillance system between 1 January 2011 and 31 December 2015 were analyzed. Multinomial logistic regression analysis was conducted to identify and compare the risk factors for international transfer-out. Results: Among the 668 foreign-born patients whose treatment outcome had been evaluated as "transferred- out", 51.3% has in fact moved to outside Japan between 2011 and 2015. The proportion of such international transfer-out of total foreign-born patients who had transferred out has more than doubled during the study period, from 23.3% in 2011 to 57.7% in 2015. Some of the risk factors for international transfer-out were being a full-time worker (Relative risk [RR] 2.86, 95% confidence interval [CI] 2.04, 3.99), being diagnosed within 0 to 2 years of arriving to Japan (RR 8.78, 95% CI 4.30,17.90) and within 3 to 5 years (RR 7.53, 95% CI 3.61, 15.68), sputum smear positive (RR 1.95, 95% CI 1.53, 2.48), and coming from Indonesia (RR 1.86, 95% CI 1.13, 3.03). Conclusions: Providing continuity of care for mobile population is one of the keys to achieving the WHO's End TB Strategy targets for 2030, and results of our study indicate that a cross-border referral system should be an integral part of TB control among foreign-born persons in Japan. © 2018 The Author(s).

Patient care Surveillance Migration Treatment outcome tuberculosis

human middle aged statistics and numerical data Internationality international cooperation Cross-Sectional Studies Young Adult Humans cross-sectional study migrant lung tuberculosis Treatment Outcome health services research male Emigrants and Immigrants Adolescent female Infant, Newborn Japan Tuberculosis, Pulmonary preschool child patient referral Infant Child, Preschool newborn Referral and Consultation evaluation study adult Child