Essebag Vidal, Genest Jacques, Suissa Samy, Pilote Louise
Division of Cardiology, McGill University Health Center, Montreal, Quebec, Canada.
Am Heart J. 2003 Oct;146(4):581-90. doi: 10.1016/S0002-8703(03)00512-X.
The nested case-control study is an efficient epidemiological design whereby a case-control approach is employed within an established cohort. The large number of recent prospective studies and randomized trials conducted in cardiology provide cohorts within which the nested case-control approach is increasingly used.
This paper describes the design of the nested case-control study, and evaluates its role in cardiology by reviewing all such studies indexed in Medline from 1966 to 2000. The example of homocysteine is used to illustrate how discrepancies between results of nested case-control and case-control studies played an important role in the decisions and recommendations of national and international organizations.
Seventy-seven nested case-control studies in cardiology were reviewed. The number of studies per year has been increasing since the first publication in 1987. The majority (96%) of studies evaluated potential risk factors for cardiovascular disease while the remainder evaluated drugs with cardiac adverse effects. In studies of homocysteine and coronary artery disease, nested case-control studies did not confirm the strong association suggested by early case-control studies that may have been influenced by bias (eg, selection, publication, or reverse causality). This led national and international organizations to advise against routine screening.
The nested case-control study is increasingly used to study causal relationships in cardiology. The large cohorts of cardiac patients created by prospective studies, clinical trials, and administrative databases should be exploited using this methodology to assess potential cardiac risk factors and other causal relationships that cannot be studied in randomized trials.
巢式病例对照研究是一种有效的流行病学设计方法，即在已建立的队列中采用病例对照研究方法。近期在心脏病学领域开展的大量前瞻性研究和随机试验提供了队列，巢式病例对照方法在这些队列中的应用越来越广泛。
本文描述了巢式病例对照研究的设计，并通过回顾1966年至2000年Medline索引的所有此类研究，评估其在心脏病学中的作用。以同型半胱氨酸为例，说明巢式病例对照研究与病例对照研究结果之间的差异如何在国家和国际组织的决策及建议中发挥重要作用。
对77项心脏病学领域的巢式病例对照研究进行了回顾。自1987年首次发表以来，每年的研究数量一直在增加。大多数研究（96%）评估了心血管疾病的潜在危险因素，其余研究评估了具有心脏不良反应的药物。在同型半胱氨酸与冠状动脉疾病的研究中，巢式病例对照研究并未证实早期病例对照研究所提示的强关联，早期研究可能受到了偏倚（如选择、发表或反向因果关系）的影响。这导致国家和国际组织建议不进行常规筛查。
巢式病例对照研究越来越多地用于研究心脏病学中的因果关系。应利用前瞻性研究、临床试验和行政数据库所产生的大量心脏病患者队列，采用这种方法来评估潜在的心脏危险因素以及随机试验中无法研究的其他因果关系。
