- 學位論文
社區肝癌篩檢的成本效果分析--比較腹部超音波篩檢及二階段篩檢
Cost-Effectiveness of Population-Based Hepatocellular Carcinoma Screening -- Comparison between Ultrasonography Screening and Two-stage Screening
摘要
在台灣肝癌是最常見的惡性腫瘤之一，並且是癌症致死率排名的首位。由於早期肝癌的症狀並不明顯，肝癌在臨床上往往在中、晚期才被診斷出來，可接受根治性治療的比率不高; 因此篩檢出早期肝癌是十分重要的。已有不少研究證實以超音波為基礎的肝癌篩檢策略可提升無症狀的小型肝癌的發現率及手術的可切除率，甚至延長患者的存活，但不同篩檢策略的成本效果如何，目前仍待釐清。 我們使用馬可夫決策分析模式，針對B 型肝炎高盛行地區的一般40歲以上社區民眾的假設世代，比較三種不同肝癌篩檢策略，包括(1)完全沒有篩檢的介入(2)以二階段篩檢為基礎的肝癌篩檢(3) 大規模的腹部超音波肝癌篩檢。我們根據過去社區肝癌篩檢的經驗，以電腦模擬肝癌的自然史，並建立不同肝癌篩檢策略的決策樹模型，以進行成本效果分析。篩檢參數的取得主要來自本土肝癌篩檢及大型世代研究的整合分析。在考量成本效果分析中的參數有其不確定性，我們使用單向敏感度分析的方法將參數值在合理範圍內調整;也使用機率性敏度分析方法將參數間的不確定性予以結合。另外，我們也嘗試比較不同的篩檢起始點及不同的篩檢間隔的成本效益。 研究結果顯示，我們的模型對肝癌死亡率的預測和國內肝癌死亡資料相比較並無差異。和沒接受篩檢比較起來，每增加一個人年的成本在大規模的腹部超音波篩檢為新台幣1874433元，在二階段的篩檢則為新台幣2164578元。大規模的腹部超音波篩檢比起二階段篩檢平均每人可多獲得0.0014年的平均餘命且只要多付出約新台幣216元的篩檢成本，因此較符合成本效果。若願意付出的上限值定在新台幣566,566元(相當於96年的台灣平均國民生產毛額)，則肝癌的篩檢策略並不符合成本效果。敏感度分析的結果，肝癌治療的存活率及肝硬化的盛行率是決定次段預防是否具成本效果的決定因子。而篩檢工具的價格及生化值篩檢的特異度是決定不同篩檢策略相對成本效果的重要因子。此外，兩年一次的篩檢間隔及50歲開始的篩檢年齡比起基礎值分析所用的40歲篩檢起始點及每年的篩檢間隔具成本效果 本研究的結論為: 社區大規模腹部超音波篩檢比二階段肝癌篩檢具成本效果，篩檢工具的價格及生化值篩檢的特異度決定相對的成本效果。50歲開始的篩檢年齡及兩年一次的篩檢間隔具最佳的篩檢成本效果。 關鍵詞: 肝癌, 二階段篩檢, 大規模腹部超音波篩檢, 馬可夫模式, 成本效果, 敏感度分析
並列摘要
Hepatocellular carcinoma (HCC) is one of the most common cancers and is the leading cause of cancer death in Taiwan. Hepatocellular carcinoma in early stage is usually asymptomatic and patients commonly manifest with advanced diseases. Curative surgery is only feasible for a few patients and it’s extremely important to make early diagnosis of HCC. Ultrasonography (US) is widely believed to be an effective form of secondary prevention for HCC and many studies showed its efficacy to increase the detecting rate of small tumor and increase the proportion of curative treatment . However there is a lack of empirical evidence showing the cost-effectiveness of US screening . A Markov model was used to estimate the expected lifetime costs and outcomes associated with screening strategies for HCC in a hypothetical cohort of 40-yr-old community residents. We compared the following strategies for HCC screening: No screening, two-stage screening and mass screening with US. Parameters of natural history , sensitivity and specificity of biochemical screenig were derived from our previous studies of two-stage liver cancer screening. Accuracy of ultrasonograpy screening , mortality associated with the specific stage of liver were based on meta-analysis. Deterministic and probabilistic sensitivity analysis were performed to assess the effects of uncertainty of parameters. We also evaluate the relative costs and effectiveness by comparing different screening strategies with different inter-screening interval and initial age. Mass screening with ultrasonography was associated with an incremental cost-effectiveness ratio of NT $1,874,433 per life-year gained whereas two-stage screening was associated with an incremental cost-effectiveness ratio of NT $ 2,164,578 per life-year gained compared with no screening .Mass screening with ultrasongoraphy seems cost-effective than two-stage screening. The screening programs intiated at the age of 50 years and with biennial screning interval have a better cost-effevtiveness ratio. In conclusion mass screening with ultrasonography, particularly intiated form 50 years of age with two inter-screening interval, is more cost-effective than two-stage screening . The relative cost-effectiveness may vary with costs of screening tools and the specificity of biochemical screening.