1 Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
2 Norwegian National Advisory Unit for Women's Health, Women's Clinic, Oslo University Hospital, Oslo, Norway.
Stat Methods Med Res. 2019 Jun;28(6):1911-1923. doi: 10.1177/0962280218778624. Epub 2018 Jun 21.
For time-to-event data, the study sample is commonly selected using the nested case-control design in which controls are selected at the event time of each case. An alternative sampling strategy is to sample all controls at the same (pre-specified) time, which can either be at the last event time or further out in time. Such controls are the long-term survivors and may therefore constitute a more 'extreme' comparison group and be more informative than controls from the nested case-control design. We investigate this potential information gain by comparing the power of various 'extreme' case-control designs with that of the nested case-control design using simulation studies. We derive an expression for the theoretical average information in a nested and extreme case-control pair for the situation of a single binary exposure. Comparisons reveal that the efficiency of the extreme case-control design increases when the controls are sampled further out in time. In an application to a study of dementia, we identified Apolipoprotein E as a risk factor using a 1:1 extreme case-control design, which provided a hazard ratio estimate with a smaller standard error than that of a 2:1 nested case-control design.
对于事件时间数据，研究样本通常使用巢式病例对照设计选择，其中对照是在每个病例的事件时间选择的。另一种采样策略是在相同的（预先指定的）时间对所有对照进行采样，这可以是在最后一次事件时间或进一步的时间。这些对照是长期幸存者，因此可能构成一个更“极端”的比较组，比巢式病例对照设计的对照提供更多的信息。我们通过使用模拟研究比较各种“极端”病例对照设计与巢式病例对照设计的功效来研究这种潜在的信息增益。我们针对单个二元暴露情况，为嵌套和极端病例对照对推导了理论平均信息量的表达式。比较结果表明，当对照进一步延迟采样时，极端病例对照设计的效率会提高。在一项痴呆症研究中，我们使用 1:1 极端病例对照设计确定了载脂蛋白 E 作为风险因素，这提供了一个危险比估计值，其标准误差比 2:1 巢式病例对照设计小。
