Maclure M
Department of Epidemiology, Harvard School of Public Health, Boston, MA 02115.
Am J Epidemiol. 1991 Jan 15;133(2):144-53. doi: 10.1093/oxfordjournals.aje.a115853.
A case-control design involving only cases may be used when brief exposure causes a transient change in risk of a rare acute-onset disease. The design resembles a retrospective nonrandomized crossover study but differs in having only a sample of the base population-time. The average incidence rate ratio for a hypothesized effect period following the exposure is estimable using the Mantel-Haenszel estimator. The duration of the effect period is assumed to be that which maximizes the rate ratio estimate. Self-matching of cases eliminates the threat of control-selection bias and increases efficiency. Pilot data from a study of myocardial infarction onset illustrate the control of within-individual confounding due to temporal association of exposures.
当短暂暴露导致罕见急性发病疾病风险的短暂变化时，可采用仅涉及病例的病例对照设计。该设计类似于回顾性非随机交叉研究，但不同之处在于仅对基础人群时间进行抽样。暴露后假设效应期的平均发病率比可使用Mantel-Haenszel估计量进行估计。效应期的持续时间假定为使发病率比估计值最大化的持续时间。病例的自我匹配消除了对照选择偏倚的威胁并提高了效率。一项关于心肌梗死发作研究的试点数据说明了由于暴露的时间关联对个体内混杂因素的控制。
