https://scholars.lib.ntu.edu.tw/handle/123456789/112827
Title: | 傾向分數混合模式於校正遵從性偏差的應用 Propensity score mixed model for correcting non-compliance bias |
Authors: | 傅俊閔 Fu, Chun-Min |
Keywords: | 傾向分數;平衡分數;不遵從;大腸癌篩檢;傾向分數混和模式;propensity score;balancing score;non-compliance;colorectal cancer screening;propensity score mixed model | Issue Date: | 2015 | Abstract: | 背景 無論是在隨機分派試驗,或是觀察性研究,例如全人口的篩檢計畫要轉介陽性病患,常會遇到不遵從(non-compliance)的問題。常使用的立意治療分析(Intention-to-treat)在不遵從者的追蹤結果不完整的情況,可能就無法使用。考慮使用兩治療組的初始的共變數資訊,我們提出傾向分數(propensity score)方法來解決這個問題。傾向分數由Rosenbaum and Rubin提出後,儘管已被廣泛使用,但以強可忽略治療分派條件(SITA, strongly ignorable treatment assignment)為基礎的平衡分數(balancing score)相關於傾向分數的邏輯仍常難以理解。 目的及方法 這篇研究的目的為 (1) 發展在SITA前提之下,使用平衡分數估計治療效果操作標準的邏輯推論。(2) 使用一個隨機分派試驗,我們呈現傾向分數混合模式如何能給予產生更細緻的平衡分數,以透過配對、分層、共變數分析,來評估治療效果。(3) 應用傾向分數混合模式於兩個隨機分派試驗,以及應用於全人口基礎的大腸癌篩檢計畫中,糞便潛血反應陽性的轉介,對於因大腸癌死亡的影響。 結果 根據以SITA為前提使用平衡分數的推導,使用隨機分派試驗資料模擬,顯示傾向分數混合模式和傾向分數固定模式比起來,可以產生更接近真實治療效果的估計。傾向分數混合模式納入隨機效果(random effect),也對治療組的遵從者(complier)和控制組的潛在遵從者(potential noncomplier)之間的比較,能產生真實治療效果的不偏估計。當傾向分數固定模式使用在大腸癌篩檢轉介大腸鏡篩檢計畫時,遵從者(接受轉介者)相對於非遵從者(不接受轉介者),死亡率相對風險為0.60 (95%信賴區間0.49 ~ 0.74),和粗死亡率相對風險比起來,只有輕微下降,但若用傾向分數混合模式,可大幅下降至0.49 (95%信賴區間0.36 ~ 0.66)。 結論 我們在SITA的假定之下,發展對於平衡分數操作的邏輯推論,並提供傾向分數分析的分析架構。接著我們提出傾向分數混合模式,讓平衡分數能夠儘量細緻,期能達到更準確的治療效果評估。傾向分數混和模式成功地應用在追蹤訊息不完整的非遵從問題,也應用在當兩治療組的基礎共變數有不平衡的情況。 Background The non-compliance problem is often encountered not only in the randomized controlled trials (RCTs) but also in observational studies, such as population-based screening program for the referral of screen-positive participants. Intentional-to-treat method often used for solving this problem in the RCTs may not be possibly applied when the follow-up outcome among the non-compliers is not available. Propensity score method is therefore proposed as an alternative by making use of information on the imbalance of baseline covariates between the two groups. In spite of its usefulness, the logics for balancing score function in relation to propensity score function based on strongly ignorable treatment assignment (SITA) are still elusive since it was proposed by Rosenbaum and Rubin. Objectives and methods The objectives of this thesis were to (1) develop philosophical logics of operational criteria using the balancing score given SITA to approximately estimate the true treatment effect; (2) demonstrate how a new propensity score mixed effect model can render the balancing score finer following (1); to approximate the true treatment effect through matching, stratification, and covariance adjustment based on one randomized controlled trial; (3) apply the PS-mixed effect model to two randomized controlled trials and also the referral of FIT (fecal immunochemical test) positive participants in nationwide population-based colorectal cancer screening. Results Based on the development of philosophical logics of operational criteria using balancing score given SITA, the simulated results using the randomized controlled trial data showed the proposed propensity score mixed-effect (PS-mixed) model rendered the estimates of efficacy closer to true treatment effect compared with the fix-effect model. The application of this propensity score mixed-effect model with the incorporation of random-effect also gave an unbiased estimate of true treatment effect by comparing the outcome of compliers in the experimental group with that of potential compliers in the control group. While the propensity score fixed-effect model was applied to colorectal cancer screening program, the efficacy of colonoscopy (the compliers (referral) versus the non-compliers(non-referral)) gave an estimate of relative rate (RR) of the risk for death from CRC of 0.60 (95% Confidence interval: 0.49 ~ 0.74), only slightly different from the crude estimate of 0.64 (95% Confidence interval: 0.52 ~ 0.78), but substantially different from the adjusted estimate of 0.49 (95% Confidence interval: 0.36 ~0.66) based on the application of the propensity score mixed-effect model. Conclusion In a nutshell, we developed philosophical logics for operational criteria pertaining to SITA and provided the analytical framework for the propensity score analysis. We then proposed the PS-mixed model to render balancing score function as fine as possible to make the estimate of treatment effect given the PS-mixed model as close as to the true treatment effect. The proposed PS-mixed model was successfully applied to the non-compliance problem encountered in the RCT while incomplete follow-up outcome is not available and also in the observational studies when the two treatment groups have the imbalance of baseline characteristics. |
URI: | http://ntur.lib.ntu.edu.tw//handle/246246/273840 | Rights: | 論文公開時間: 2015/9/14 論文使用權限: 同意有償授權(權利金給回饋學校) |
Appears in Collections: | 流行病學與預防醫學研究所 |
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ntu-104-P02849005-1.pdf | 23.32 kB | Adobe PDF | View/Open |
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