Sampling strategies for selecting general population comparison cohorts
Sampling strategies for selecting general population comparison cohorts
复制标题
DOI：
10.2147/clep.s164456
复制
发表时间：
2018-01-01
影响因子：
3.9
通讯作者：
Pedersen, Lars
中科院分区：
文献类型：
--
作者：
Heide-Jorgensen, Uffe;Adelborg, Kasper;Pedersen, Lars
背景资料：对于一个患者队列，访问基于人群的登记研究允许从一般人群中抽取比较队列，从而有助于在人群背景下了解疾病。然而，随机顺序抽样而不替换可能会导致不朽的时间偏差，因为它是以未来为条件的。目的：我们比较了在匹配队列研究中关于缺血性卒中时间和死亡率的抽样比较队列的以下策略：随机顺序抽样而不替换;替换抽样;以及按时间顺序抽样而不替换。方法：我们从丹麦一般人群中构建了索引队列，这些人群没有特殊的特征，除了在索引日期活着并且没有缺血性卒中。我们还从一般人群中构建了年龄>50岁的人的指数队列。然后，我们将抽样策略应用于丹麦一般人群的样本比较队列（5：1或1：1），并比较指数队列和比较队列之间的结局风险。最后，我们使用每种策略对心力衰竭队列进行了比较队列的抽样。结果：与指标队列相比，我们观察到以5：1抽样的比较队列（无随机顺序替换）的结局风险增加。然而，除非指标人员年龄超过50岁，否则这些增长微不足道。在这种情况下，按时间顺序不进行替换的采样未能对足够数量的对照药物进行采样，这些比较队列的死亡风险低于索引队列。1：1采样显示比较队列和索引队列之间无系统性差异。当我们对心力衰竭患者的比较队列进行采样时，我们观察到了与指标人群年龄>50岁时相似的模式。结论：当指标人群年龄>50岁时，即具有高结局风险时，5：1采样而不替换引入了偏倚。替换抽样或1：1抽样未引入偏倚。
Background: For a patient cohort, access to linkable population-based registries permits sampling of a comparison cohort from the general population, thereby contributing to the understanding of the disease in a population context. However, sampling without replacement in random order can lead to immortal time bias by conditioning on the future.Aim: We compared the following strategies for sampling comparison cohorts in matched cohort studies with respect to time to ischemic stroke and mortality:sampling without replacement in random order; sampling with replacement; and sampling without replacement in chronological order.Methods:We constructed index cohorts of individuals from the Danish general population with no particular trait, except being alive and without ischemic stroke on the index date. We also constructed index cohorts of persons aged >50 years from the general population. We then applied the sampling strategies to sample comparison cohorts (5:1 or 1:1) from the Danish general population and compared outcome risks between the index and comparison cohorts. Finally, we sampled comparison cohorts for a heart failure cohort using each strategy.Results: We observed increased outcome risks in comparison cohorts sampled 5:1 without replacement in random order compared to the index cohorts. However, these increases were minuscule unless index persons were aged >50 years. In this setting, sampling without replacement in chronological order failed to sample a sufficient number of comparators, and the mortality risks in these comparison cohorts were lower than in the index cohorts. Sampling 1:1 showed no systematic difference between comparison and index cohorts. When we sampled comparison cohorts for the heart failure patients, we observed a pattern similar to when index persons were aged >50 years.Conclusion: When index persons were aged >50 years, ie, had high outcome risks, sampling 5:1 without replacement introduced bias. Sampling with replacement or 1:1 did not introduce bias.