Division of Hematology and Oncology, University of Alabama at Birmingham, Birmingham, AL, USA.
Department of Surgery, Boston University, Boston, MA, USA.
J Natl Cancer Inst. 2023 May 8;115(5):530-538. doi: 10.1093/jnci/djad031.
Patients with cancer living in rural areas have inferior cancer outcomes; however, studies examining this association use varying definitions of "rural," complicating comparisons and limiting the utility of the results for policy makers and future researchers.
Surveillance, Epidemiology, and End Results data (2000-2016) were used to assess risk of cancer mortality and mortality from any cause across 4 definitions of rurality: Urban Influence codes (UIC), National Center for Health Statistics (NCHS), Rural-Urban continuum codes (RUCC), and Index of Relative Rurality. Binary (urban vs rural) and ternary (urban, micropolitan, rural) definitions were evaluated. Multivariable parametric survival models estimated hazards of mortality overall and among 3 cancer groupings: screening related, obesity related, and tobacco related. Definition agreement was also assessed.
Overall, 3 788 273 patients with an incident cancer representing 605 counties were identified. There was little discordance between binary definitions of rural vs urban and moderate agreement at the 3 levels. Adjusted models using binary definitions revealed 15% to 17% greater hazard of cancer mortality in rural compared with urban. At the 3 levels when comparing rural with metropolitan, RUCC and NCHS saw similarly increased hazard ratios; however, Index of Relative Rurality did not. Screening-related cancers saw the highest hazards of mortality and the largest divergence between definitions. Obesity-related and tobacco-related cancers saw similarly increased hazards of mortality at the binary and ternary levels.
Hazard of death is similar across binary definitions; however, this differed when categorized as ternary or continuous, especially among screening-related cancers. Results suggest that study purpose should direct choice of definitions and categorization.
农村地区癌症患者的癌症预后较差；然而，研究这一关联的研究使用了不同的“农村”定义，这使得比较变得复杂，并限制了研究结果对政策制定者和未来研究人员的效用。
利用监测、流行病学和最终结果数据（2000-2016 年），评估了 4 种农村定义下的癌症死亡率和任何原因导致的死亡率风险：城市影响代码（UIC）、国家卫生统计中心（NCHS）、城乡连续体代码（RUCC）和相对农村指数。评估了二元（城市与农村）和三元（城市、小城市、农村）定义。多变量参数生存模型总体和 3 个癌症分组（筛查相关、肥胖相关和烟草相关）中估计了死亡率的风险。还评估了定义的一致性。
总体而言，确定了 3788273 名患有癌症的患者，这些患者代表了 605 个县，年龄在 0 至 104 岁之间。农村与城市的二元定义之间几乎没有差异，而在 3 个层次上有中度一致性。使用二元定义的调整模型显示，农村的癌症死亡率比城市高 15%至 17%。在比较农村与大都市的 3 个层次上，RUCC 和 NCHS 看到了相似的风险比增加；然而，相对农村指数则没有。与筛查相关的癌症死亡率风险最高，而且在定义之间存在最大差异。肥胖相关和烟草相关的癌症在二元和三元水平上都看到了类似的死亡率风险增加。
在二元定义中，死亡风险是相似的；然而，当分类为三元或连续时，情况就不同了，特别是在与筛查相关的癌症中。结果表明，研究目的应指导定义和分类的选择。
