Colorectal Cancer Screening:Evaluating Trends & Outcomes

描述（由申请人提供）本研究拟建立微观模拟模型，在华盛顿西部的一家大型卫生组织——团体健康合作社（GHC）的50多万成员中，研究筛查对观察到的结直肠癌（CRC）发病率和死亡率趋势的影响。有关这一人群的广泛信息可从自动临床数据系统获得，该系统捕获多个卫生保健事件，包括实验室检查（FOBT）和内窥镜检查程序的日期和结果、药房使用情况、门诊医生就诊和住院情况。GHC和西华盛顿SEER之间已建立的联系将用于确定这一定义人群中的结直肠癌病例，并将使用基于人群的GI病理登记来确定GHC成员中的非恶性结果（例如晚期腺瘤）。拟议的研究将涉及三个主要目标：

DESCRIPTION (provided by applicant)The proposed research develops microsimulation models to examine the effect of screening as practiced on observed trends in colorectal cancer (CRC) incidence and mortality in a defined population of over 500,000 members of Group Health Cooperative (GHC), a large HMO in western Washington. Extensive information about this population is available from automated clinical data systems that capture multiple health care events, including dates and results of laboratory tests (FOBT) and endoscopy procedures, pharmacy utilization, outpatient physician visits and hospitalizations. An established link between GHC and the westem Washington SEER will be used to identify CRC cases in this defined population and a population-based registry of GI pathology will be used to identify non-malignant outcomes (e.g. advanced adenomas) among GHC members. The proposed research will address 3 primary aims: Aim 1: Develop a microsimulation model for colorectal cancer that describes natural history, screening, diagnosis, and mortality: The model we propose takes distributional functions as inputs for unknown parameters, rather than fixed values. The proposed model has at least four key advantages over previous strategies: 1) The model incorporates uncertainty in model inputs; 2) It allows incorporation of correlation between model parameters through their distributional forms; 3) Its use of distributions as inputs essentially automates sensitivity analyses and offers an important advantage over univariate sensitivity analysis; and 4) The model produces distributional estimates for outputs, quantifying their uncertainty. Aim 2: Model the effect of screening and polypectomy on the trends in CRC incidence and mortality within the Group Health Population aged 50 and older. Our model will use data describing dissemination of screening within this population, allowing us to examine the relationship between screening at GHC and trends in rates. Aim 3: Model the combined effect of HRT, screening and polypectomy on trends in CRC incidence within the female Group Health Population aged 50 and older. HRT has been shown to reduce the incidence and perhaps improve mortality from colorectal cancer. Our third aim will allow us to explore mechanisms for this reduction in risk, such as changes in the risks for adenomatous polyps, decreases in their transition to preclinical cancer, and lengthening of sojourn time.