【原】该项临床研究属于何种医学研究类型

妙趣横生统计学 2020-03-13

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《英国医学会杂志》（BMJ）自2008年9月开始至2015年由两位流行病与统计学专家不间断地出了300多期statistical question系列。在这个系列中，两位学者每次出一道统计学选择题，进行选择并解释。现在我精选300道Statistical Question，形成中文版，请有兴趣的朋友们进行回答。

最近5期统计问题

9.相对危险度（RR）的置信区间，哪一项可能是对的?

10.随机对照试验的“风险”，你会计算吗？

11.它是正态分布、二项分布还是泊松分布？

12.样本量不够，I 型错误和 II 型错误会怎么变化？

13. 抽样调查中的应答率偏低，产生什么样的偏倚？

统计问题（14）：继续研究设计的探讨

一位神经科医生想研究偏头痛患者中风和短暂性脑缺血发作的风险。从她的临床头痛患者中，她选择了偏头痛病例作为一组，不是偏头痛的作为对照组。五年后，她通过回访收集了所有受试者发生中风和短暂性脑缺血的情况。比较偏头痛组和非偏头痛组中风风险。

Question

A neurologist wanted to study the risk of stroke and transient ischaemic attack in people with a diagnosis of migraine. From her headache clinic she selected cases of migraine and controls without migraine.She collected stroke and transient ischaemic attack outcomes by writing to allsubjects and their general practitioners five years later. Which study designbest describes what was done?

a) Ecological study

b) Cohort study

c) Clinical trial

d) Case-control study

Answer

The case control design looks at the end of a disease or process. Patients are recruited into the study in two groups. One group, the cases, has already had an outcome and the other group, the controls, has not. The question is then posed as to what these two groups of people did in the past.

Despite the wording in this study “cases” of migraine and “controls” without migraine are in fact the beginning of a study looking forward over time to the final outcome of stroke or transient ischaemic attack. This makes the study a cohort study. Migraine is examined as a potential risk factor. In this study migraine is not the outcome but the exposure.

An ecological study might compare hospital stroke admissions data with prescriptions of migraine medication on a county by county basis throughout the United Kingdom.

A clinical trial is an experiment. The clinical investigator decides what intervention each person will receive and then follows each person over time to observe the effects. As described, the above study does not involve any such intervention.

中文解释：

病例对照设计着眼于疾病或过程的终结。将患者分为两组，一组（病例组）已经有结果，而另一组（对照组）没有结果。然后提出关于这两组人过去做过的问题。

尽管本研究中的措词是偏头痛的“病例组”和不是偏头痛的“对照组”，但实际上是一项研究的开始，随着时间的流逝，我们期待中风或短暂性脑缺血发作的作为最终结果。这使该研究成为队列研究。偏头痛被视为潜在的危险因素。在这项研究中，偏头痛不是结果，而是暴露因素。

一项生态研究可能会比较整个英国各地县的医院卒中入院数据与偏头痛药物的处方。

临床试验是一项实验性研究。临床研究者决定每个人将接受什么干预，然后随着时间的推移记录每个人健康结局。但本项研究不涉及任何此类干预。

所以答案是选择 B（队列研究）