Charlton Mary E, Matthews Kevin A, Gaglioti Anne, Bay Camden, McDowell Bradley D, Ward Marcia M, Levy Barcey T
Department of Epidemiology, University of Iowa College of Public Health, Iowa City, Iowa.
Department of Geography, University of Iowa, Iowa City, Iowa.
J Rural Health. 2016 Sep;32(4):363-373. doi: 10.1111/jrh.12159. Epub 2015 Nov 26.
Colorectal cancer (CRC) screening has been shown to decrease the incidence of late-stage colorectal cancer, yet a substantial proportion of Americans do not receive screening. Those in rural areas may face barriers to colonoscopy services based on travel time, and previous studies have demonstrated lower screening among rural residents. Our purpose was to assess factors associated with late-stage CRC, and specifically to determine if longer travel time to colonoscopy was associated with late-stage CRC among an insured population in Iowa.
SEER-Medicare data were used to identify individuals ages 65 to 84 years old diagnosed with CRC in Iowa from 2002 to 2009. The distance between the centroid of the ZIP code of residence and the ZIP code of colonoscopy was computed for each individual who had continuous Medicare fee-for-service coverage for a 3- to 4-month period prior to diagnosis, and a professional claim for colonoscopy within that time frame. Demographic characteristics and travel times were compared between those diagnosed with early- versus late-stage CRC. Also, demographic differences between those who had colonoscopy claims identified within 3-4 months prior to diagnosis (81%) were compared to patients with no colonoscopy claims identified (19%).
A total of 5,792 subjects met inclusion criteria; 31% were diagnosed with early-stage versus 69% with late-stage CRC. Those divorced or widowed (vs married) were more likely to be diagnosed with late-stage CRC (OR: 1.20, 95% CI: 1.06-1.37). Travel time was not associated with diagnosis of late-stage CRC.
Among a Medicare-insured population, there was no relationship between travel time to colonoscopy and disease stage at diagnosis. It is likely that factors other than distance to colonoscopy present more pertinent barriers to screening in this insured population. Additional research should be done to determine reasons for nonadherence to screening among those with access to CRC screening services, given that over two-thirds of these insured individuals were diagnosed with late-stage CRC.
结直肠癌（CRC）筛查已被证明可降低晚期结直肠癌的发病率，但仍有相当一部分美国人未接受筛查。农村地区的居民可能因路途时间而面临结肠镜检查服务的障碍，并且先前的研究表明农村居民的筛查率较低。我们的目的是评估与晚期结直肠癌相关的因素，特别是确定在爱荷华州的参保人群中，较长的结肠镜检查路途时间是否与晚期结直肠癌有关。
利用监测、流行病学和最终结果（SEER）-医疗保险数据，识别出2002年至2009年在爱荷华州被诊断为结直肠癌的65至84岁个体。对于在诊断前连续3至4个月拥有医疗保险按服务付费覆盖且在此时间段内有结肠镜检查专业索赔记录的每个个体，计算其居住邮政编码中心与结肠镜检查邮政编码之间的距离。比较早期和晚期结直肠癌患者的人口统计学特征和路途时间。此外，还比较了在诊断前3至4个月内有结肠镜检查索赔记录的患者（81%）与无结肠镜检查索赔记录的患者（19%）之间的人口统计学差异。
共有5792名受试者符合纳入标准；31%被诊断为早期结直肠癌，69%被诊断为晚期结直肠癌。离婚或丧偶者（相对于已婚者）更有可能被诊断为晚期结直肠癌（比值比：1.20，95%置信区间：1.06 - 1.37）。路途时间与晚期结直肠癌的诊断无关。
在医疗保险参保人群中，结肠镜检查的路途时间与诊断时的疾病分期之间没有关系。在这个参保人群中，距离结肠镜检查地点的远近之外的其他因素可能对筛查构成了更相关的障碍。鉴于超过三分之二的这些参保个体被诊断为晚期结直肠癌，应该进行更多研究以确定有机会获得结直肠癌筛查服务的人群中不坚持筛查的原因。
