The Cost-effectiveness Analysis Of Active Chest X Ray Screening For Tuberculosis In Mass Populations And The Study Of Distinguishing NTM And MDR-TB From Tuberculosis In China

This study was divided into two parts.Part A:The cost-effectiveness analysis of active chest X ray screening for tuberculosis in mass populationsBackgroud:Currently, the discovery rate of TB is less than20%according to a national TB epidemiological survey. Hence, how to improve the strategies to enhance the detection and revealing of TB becomes the key to prevent and control of the disease. An active large-scale population screening tactic of TB through chest X-ray has been launched in the Demonstration Zone of the prevention and treatment of infectious diseases in Zhejiang Province since2009. And477,200patients with920,000man times of TB screening were completed in the end of2012. This article explores the contribution of the strategy to improve the revealing of TB, while establishing effective evaluation method via creating TB Markov model to assess the strategy in a health economic perspective.Objectives:To investigate the contribution of active chest X-ray screening in improving the revealing of TB and establish effective evaluation method via creating TB Markov model to assess the strategy in a health economics perspective.Methods:We analyzed the data of Chest X-ray screening of477,200individuals to obtain the prevalence rate of population of TB and compared with the reported prevalence of local area to assess the contribution of the strategy in improving the revealing rate. Also a TB control evaluation system is established from3dimensions (cost-effectiveness, cost-utility and cost-benefit). Another model is also created on the base of Markov module in Treeage2011to simulate the trends of TB epidemic situation in a large population and to calculate the impact, which, will provide support for health economics evaluation.Results:393cases of pulmonary TB were discovered in477,200individuals, implying that the probable prevalence is82.36/100,000, or112/100,000when standardized by the population structure in Zhejiang Province, which means the TB detection rate was improved by22%through the implementation of comparison strategy. According to the established evaluation system, the cost-benefit of the strategy will reach1.8when it is conducted in the whole population, while a higher benefit ratio will be observed in a high-risk group. According to the Markov model of TB, the diagnosis level also was improved while implementing the strategy with the increased detection rate of80%, which can significantly accelerate the epidemic control and breed enormous social benefits; simultaneously, a predictive epidemic chart was procured, and3key factors of epidemic prevention were figured out-i.e. the population MTB infective rate, the risk of latent MTB infection which could progress to active TB and the diagnostic rate of TB, which are supposed to be solved on focus.Conclusions:1) An active Chest X-ray screening in large population has positive benefits with an increase revealing rate of TB by22%and a cost-benefit ratio of1.82, which proves to be worthy to promote and will achieve higher profit when implementing in high-risk population of TB.2) the cost-effective measure approach of TB can evaluate the cost-effectiveness, cost-utility and cost-benefit mathematically. The discovery of one TB patient could protect at least5healthy individuals from MTB infection, avoid the occurrence of0.5TB, restore6.825DALY and obtain social benefit approximately to260,000CNY.3) a predictive epidemic chart was procured via Markov TB model, and3key factors of epidemic prevention were figured out-i.e. the population MTB infective rate, the risk of latent MTB infection which could progress to active TB and the diagnostic rate of TB, which are supposed to be solved on focus. Part B:The study of distinguishing NTM and MDR-TB from tuberculosis in chinaBackground:Postitive acid-fast bacillus test of sputum smear remains the only bacteriological basis of pulmonary tuberculosis diagnosis in many primary medical organizations, lacking Mycobacterium culture, species identification or drug-resistance test, therefore patients with NTM are facilitated misdiagnosed with tuberculosis and MDR infection can’t be diagnosed accurately. All the patients, infected with NTM or MDR, receive the same standard anti-tuberculous Protocols by mistake, leading to a long-last exist of the disease itself and infectivity to other people. Hence, to master the MDR or NTM patients’percentages in all the "tuberculous" patients first diagnosed by primary medical organizations will be very important for revising and improving Tuberculosis (TB) prevention and control strategy.Objectives:To master the MDR or NTM patients’percentages in all the "tuberculous" patients first diagnosed by primary medical organizations, comprehending the major prevalent NTM species and to clarify the dominant molecular mutation types in INH-or RFP-resistant tuberculosis.Method:To analyze the prevalence of MDR and NTM infection by INH-/RFP-resistance mutation test and mycobacterium species identification using gene chip technology on the basis of1410tuberculous strains and corresponding patients’epidemiology data collected from8infectious diseases prevention and control counties in Zhejiang province.Results:166NTM and MDR strains are detached from total1410strains, taking a percentage of11.8%. The major prevalent NTM species in Zhejiang province are M.avium, M. kansasii, and M. chelonae. katG315is the chief prevalent mutation site for INH-resistance, taking a percentage of81.4%while rpoB531is the main prevalent mutation site for RFP-resistance by60.0%.Conclusions:1) In order to make a definite diagnosis of NTM and MDR patients, to provide Individualized and effective therapeutic regimen, Mycobacterium identification and drug-resistance testing technology should be popularized as soon as possible in our country. If the standard anti-tuberculous Protocols were still given without accurate diagnosis, about10%of all the acid-fast bacillus test positive patients would fail to be cured, also the NTM and MDR pandemic would increase.2) katG315and rpoB531are the main prevalent mutation sites in INH-/RFP-resistant strains, respectively, to which high attention should be paid in surveillance of drug-resistant mycobacteria prevalence.3) M.avium, M. kansasii, and M. chelonae are the most common NTM species in Zhejiang province. Diagnosis and distinguish of these mycobacterium infections should be more careful in clinical works.