The Effect of Risk Factor Control on Tuberculosis in Taiwan: A Modelling Study

• Main Authors: Chih-Hui Wang, 王稚慧
• Other Authors: Hsien-Ho Lin
• Format: Others
• Language: en_US
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/87581996178100694559

碩士 === 國立臺灣大學 === 流行病學與預防醫學研究所 === 104 === Background In the new End TB Strategy, management of TB risk factors, including smoking, alcohol use, diabetes, and underweight, is considered to be a critical component. Few studies have assessed the impact of reducing multiple risk factors on future trend of TB incidence at the national level. The aim of this study is to evaluate the effect of risk factors control on TB incidence in Taiwan. Methods We constructed a compartmental model with age structure for tuberculosis transmission, and calibrated the model to the trend of TB incidence in Taiwan. Smoking, alcohol use, diabetes, and underweight were assumed to affect the parameters related to tuberculosis natural history in the model, following the results of previous systematic reviews. We constructed future scenarios of risk factor control based on the World Health Organization’s Noncommunicable Disease (NCD) control targets and the Sustainable Development Goals. The effect of risk factors control was evaluated by comparing the percentage of reduction in TB incidence under different scenarios between 2015 and 2035. Results In base case scenario, if current tuberculosis control measures remain unchanged and all the risk factors follow the current trend (decreasing prevalence of smoking and underweight, stable trend of alcohol use, and increasing prevalence of diabetes), the cumulative reduction of TB incidence would only be 4.6% (95% UI: -20.3 to 2.3) in 2015-2035. Compared with the base case scenario, the TB incidence would be further reduced by 2.9% (95% UI: -4.1 to -1.7) if the target of alcohol use reduction is achieved. If diabetes stops rising after 2015, the relative reduction in cumulative TB incidence would be 9.7% (95% UI: -13.5 to -6.1). In the scenario of end hunger, the relative reduction would be 0.8% (95% UI: -1.2 to -0.5) if the prevalence of underweight reduces to zero by 2030. However, if the prevalence of smoking stops declining, the relative increase in cumulative TB incidence would be 5.1% (95% UI: 2.5 to 7.6). For the interventions on multiple risk factors, achieving the targets of alcohol use reduction, diabetes stop rising, and ending hunger simultaneously would result in further 11.6% (95% UI: -15.3 to -7.8) reduction in cumulative TB incidence compared with the base case scenario. If all risk factors reduce to zero by 2030, the relative reduction would be 36.0% (95% UI: -47.1 to 24.0) by 2035. Conclusions Our study indicates that controlling the risk factors at the population level could reduce TB burden. Among the four risk factors considered, the impact of diabetes control would be the greatest given to the observed rising trend of diabetes. Coordinated efforts between the national TB program and the NCD program will be required to help achieve the target of the End TB strategy.