台灣肺結核都治計畫的經濟評估

Directly observed therapy-short course (DOTS) in Taiwan---economic evaluation

鐘威昇(Wei-Sheng Chung)

指導教授 ： 楊銘欽

國立臺灣大學/公共衛生學院/醫療機構管理研究所/博士(2008年)

https://doi.org/10.6342/NTU.2008.03003

摘要

肺結核不僅會傳染他人，也會使人罹病，甚至造成死亡。一旦感染肺結核發病至少需要經六個月的藥物治療，治療期間不僅造成病人不適，可能遭受排擠，也會增加家人、衛生單位(衛生署疾病管制局、衛生局、衛生所)工作人員、健保局、及醫療機構的醫療及社會成本。肺結核病人如果沒有規則治療，失落或治療失敗造成抗藥結核所導致的社會成本更會增加，因此肺結核已經變成世界各國重要的公共衛生、社會、及經濟議題。肺結核若不經治療，一年可能傳染十至十五人，並且未規則服藥也容易產生抗藥性肺結核，增加治療的困難度。
台灣於2006年4月正式實施都治計畫，投入了相當多的人力及物力，期望提高成功治療率，及降低發生率。以往肺結核的研究著重在治療的結果，缺乏以經濟評估的方法做深入的研究。故本研究的目的除了探討都治計畫對肺結核治療結果(治療成功及死亡)的影響外，更以成本效果分析都治計畫及自我服藥(沒有都治計畫)的成本效果比，並以馬可夫(Markov)決策模式推估都治計畫對結核病族群十年、二十年及三十年的影響及經濟評估。本研究可提供台灣本土都治計畫的經濟評估，有別於其他文獻未考量失落及治療失敗的抗藥問題，而本研究將失落及治療失敗衍生抗藥問題的成本亦列入考量。
本研究共分三大部分：第一部分是是探討影響結核病患治療成功及死亡的因子；研究對象是2006年1月1日至2006年12月31日嘉義縣、市以及台北縣、市以及花蓮縣、台東縣新通報且確診並開始使用結核藥物的個案，追蹤一年觀察其治療結果。第二部分是評估都治計畫對治療結果的成本效果比，以社會觀點論，折現值採3%，以決策樹分析都治計畫對肺結核個案的成本效果。第三部份則是以一群40歲至44歲的15,000位結核病人族群，以馬可夫決策模式推估都治計畫參與對這群結核病族群十年及終生(約三十年)的影響。
本研究的結果顯示在控制其他變項後，發現參與都治計畫者比沒有參與都治計畫者有2.84倍高的治療成功勝算率；沒有參與都治計畫者比參與都治計畫者有2.78倍高的死亡勝算率。成本效果方面，研究顯示都治計畫的實施增加病人的治療成功率，減少了治療失敗及死亡的個案；經過成本效果分析顯示都治計畫的實施不僅成本較低，且效果較高，成本效果比為111,991元明顯優於沒有實施都治計畫的成本效果比143,349元。
馬可夫決策模式估計都治計畫對結核病族群的影響，不論十年、二十年及三十年，因為都治計畫的實施，總成本都比較低，且隨著都治計畫參與率越高總成本越低；總效果也因為都治計畫的實施而升高，並且隨著都治計畫參與率越高總效果越高。結核病人治癒且持續緩解的人數也隨著都治計畫參與率越高而增加。結核病死亡的人數也隨著都治計畫參與率越高而降低。由於都治計畫的實施，關懷員人力的訓練及投入，親眼目睹結核病患服下足夠劑量的抗結核藥物，並提供營養補助及完治獎金的誘因。僅管一開始都治計畫投入的費用比病患自我服藥來的多。但是隨著時間的進行即可看出都治計畫的效果，減少結核死亡及復發的個案進而減少總成本，提升總效果。肺結核的治療成功可以防止肺結核繼續傳染給他人及減少抗藥的產生。本研究應用決策模式作評估，並以社會的觀點來看時，相對於沒有實施都治計畫，都治計畫的實施具有絕對的優勢，並且都治計畫的參與率愈高愈是成本節約的方案。台灣實施都治計畫是一符合經濟效果的好政策。

關鍵字

肺結核 ； 都治計畫 ； 治療成功 ； 成本效果分析 ； 馬可夫決策模式

並列摘要

Mycobacterium tuberculosis not only infects human being but also causes morbidity and mortality. People who contract tuberculosis should take antituberculosis medicine for at least 6 months. During treatment, these patients may suffer from side effects of the drugs and also incur social stigma. Moreover, pulmonary tuberculosis (TB) could increase the social cost of the patients, their families, healthcare units and the society. Multi-drug resistance TB may result from those who did not follow regular treatment. Therefore, TB becomes one of the important issues of public health, social, and economic problems in the world.
Directly observed therapy short-course (DOTS) had been launched in Taiwan since 2006. The government expected to increase the treatment success rate and decrease the incidence rate by investing human resources and financial support. Exisiting studies of TB were mostly focused on the treatment outcome in lack of economic evaluation. Therefore, the aims of the study were to investigate the effect of DOTS on the treatment outcome (treatment success and TB death), to evaluate the economic impact of the DOTS by using decision tree, and to estimate the impact of DOTS on the TB cohort for 10 years and lifetime by using the Markov model. Discount rate was introduced by 3 % and cost evaluation was adopted from social perspectives
The result of the study displayed that after adjusting other variables, the probability of treatment success in DOTS group was 2.84 times higher than that of self administered therapy (non-DOTS) group. The death probability of self administered therapy group was 2.78 times higher than that of DOTS group. Cost effectiveness ratio revealed that 111,991 NTD on DOTS group, which was better than self administered therapy group (143,349 NTD).
Markov model displayed that the total cost of DOTS implementation was lower than that of self administered therapy group. Moreover, total cost was progressively lower in accordance with increasing participating in DOTS rate for 10 years, 20 years and 30 years as well. Total effect of DOTS implementation was higher than that of self administered therapy. Besides, total effect became higher in accordance with increasing participating in DOTS rate for 10 years, 20 years and 30 years as well. Furthermore, the numbers of TB cases and TB death after DOTS implementation were lower than that of self administered therapy. In addition, the numbers of TB cases and TB death became lower in accordance with increasing participating in DOTS rate for 10 years, 20 years and 30 years as well.
To bring into force of DOTS, training of the healthcare workers and providing nutritional incentives for TB patients, DOTS program must deliver enough doses of medications to patients to ensure compliance. Despite that DOTS program increased the expense at the onset, but it is cost effectiveness in the long run. One of the major benefits of effective treatment of active TB is the prevention of further transmission and decreasing the drug resistance TB emergence.
The study could not evaluate the cost of the drug interaction and side effects on treatment of TB and co-morbidities, which might be our limitation. The study also could not evaluate psychological costs of social stigmatization and ostracism which might be another limitation. In conclusion, the DOTS program implemented in Taiwan was a cost effectiveness program.

並列關鍵字

pulmonary tuberculosis ； directly observed therapy short-course ； treatment success ； cost effectiveness analysis ； Markov model

參考文獻

39.Chiang CY, Hsu CJ, Huang RM, Lin TP, Luh KT. Antituberculosis drug resistance among retreatment tuberculosis patients in a referral center in Taipei. J Formos Med Assoc 2004;103:411-5.

3.Center for Disease Control. Tuberculosis Annual Report 2005. Taipei, Taiwan: Center for Disease Control, Department of Health 2006

32.許建邦、羅秀雲、李政益、楊祥麟、王貴鳳、楊世仰. 台灣都治（ DOTS）執行經驗及成效初探。疫情報導2008;24:184-203.

12.Yu MC, Suo J, Huang C, Bai KJ, Lin TP, Luh KT. Annual risk of tuberculous infection in Taiwan, 1996-1998. J Formos Med Assoc. 1999; 98:496-9.

2.Cheng SH, Chiang TL. The effect of universal health insurance on health care utilization in Taiwan. Results from a natural experiment. JAMA 1997;278:89-93.