Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
Department of Health Sciences, University of Leicester, Leicester, United Kingdom.
Am J Epidemiol. 2018 Apr 1;187(4):828-836. doi: 10.1093/aje/kwx303.
Expected or reference mortality rates are commonly used in the calculation of measures such as relative survival in population-based cancer survival studies and standardized mortality ratios. These expected rates are usually presented according to age, sex, and calendar year. In certain situations, stratification of expected rates by other factors is required to avoid potential bias if interest lies in quantifying measures according to such factors as, for example, socioeconomic status. If data are not available on a population level, information from a control population could be used to adjust expected rates. We have presented two approaches for adjusting expected mortality rates using information from a control population: a Poisson generalized linear model and a flexible parametric survival model. We used a control group from BCBaSe-a register-based, matched breast cancer cohort in Sweden with diagnoses between 1992 and 2012-to illustrate the two methods using socioeconomic status as a risk factor of interest. Results showed that Poisson and flexible parametric survival approaches estimate similar adjusted mortality rates according to socioeconomic status. Additional uncertainty involved in the methods to estimate stratified, expected mortality rates described in this study can be accounted for using a parametric bootstrap, but this might make little difference if using a large control population.
预期或参考死亡率通常用于计算基于人群的癌症生存研究和标准化死亡率比等指标。这些预期比率通常根据年龄、性别和日历年份呈现。在某些情况下，如果研究兴趣是根据社会经济地位等因素来量化指标，则需要按其他因素对预期比率进行分层，以避免潜在的偏差。如果没有关于人群的数据，则可以使用对照人群的信息来调整预期比率。我们提出了两种使用对照人群信息调整预期死亡率的方法：泊松广义线性模型和灵活参数生存模型。我们使用了来自瑞典 BCBaSe 的一个基于登记的、匹配的乳腺癌队列的对照组，该队列的诊断时间在 1992 年至 2012 年之间，以社会经济地位作为感兴趣的风险因素来说明这两种方法。结果表明，泊松和灵活参数生存方法根据社会经济地位估计相似的调整死亡率。本研究中描述的分层预期死亡率估计方法所涉及的额外不确定性可以使用参数自举来解释，但如果使用大型对照组，这可能影响不大。
