Department of Clinical Epidemiology and Biostatistics, University of Pennsylvania, Philadelphia, PA 19104, USA.
Stat Med. 2010 Jun 15;29(13):1360-7. doi: 10.1002/sim.3635.
The National Children's Study (NCS) is a unique study of environment and health that will follow a cohort of 100 000 women from prior to or early in pregnancy and then their children until 21 years of age. The NCS cohort will be a national multi-stage probability sample, using a U.S. Census Bureau geographic sampling frame unrelated to factors that might influence selection into the sample (e.g. access to health care). I present the case for the use of a national probability sample as the design base for the NCS, arguing that selection of the original cohort should be as free from selection bias as possible. The dangers of using a selected or nonprobability sample approach are demonstrated by an example of its use in outlining the clinical management of children with febrile seizures, an infrequent disorder, which was so wrong for decades. In addition, I stress the importance of and the NCS approach to avoiding selection bias that might occur after the initial selection of the cohort. The selection of and maintenance of an unselected cohort is an important element for the validity of inferences in this major undertaking.
国家儿童研究（NCS）是一项独特的环境与健康研究，将对 100,000 名妇女进行跟踪研究，这些妇女来自怀孕前或怀孕初期，然后对其子女进行跟踪研究，直到 21 岁。NCS 队列将是一个全国多阶段概率样本，使用美国人口普查局的地理抽样框架，与可能影响样本选择的因素（例如获得医疗保健）无关。我提出了使用全国概率样本作为 NCS 设计基础的理由，认为原始队列的选择应尽可能避免选择偏差。通过一个例子来说明选择或非概率样本方法的危险，该例子概述了儿童热性惊厥的临床管理，这是一种罕见的疾病，几十年来一直存在错误。此外，我强调了避免在队列最初选择后可能出现的选择偏差的重要性和 NCS 方法。选择和维持未经选择的队列是这项重大任务中进行推论的有效性的重要因素。
