Stager J M, Wigglesworth J K, Hatler L K
Department of Physical Education, Indiana University, Bloomington 47405.
Med Sci Sports Exerc. 1990 Feb;22(1):54-8.
It has been concluded from studies using retrospective data and thus quasi-experimental designs that menarche may be delayed by prepubertal athletic training. Furthermore, a causal relationship between the age of initiation of training (AIT) and the age of menarche (AOM) has been proposed. To investigate the possibility that these conclusions were erroneous and based upon analytical artifact, a computer program was used to generate random and independent AOM and AIT for a population of 30,000 "athletes". The generated mean AOM (means = 13.4 yr) and mean AIT (means = 10.0 yr) were similar to those reported in recent literature. The sampling procedure was designed such that no relationship existed between AOM and AIT in these hypothetical athletes (r = 0.002). When two subgroups (pre- or post-menarcheal training) were compared, the pre-training group was found to have a significantly later AOM than the post-trained group (means = 13.9 yr vs means = 11.7 yr; P less than 0.05). Significant correlations were found for each subgroup between AOM and AIT (r = 0.46 and 0.40 pre- and post-menarcheal training, respectively), similar to values previously reported. In conclusion, the sampling procedures performed in the present study and in similar data sets result in biased estimates of the statistical parameters. This bias accounts for the reported relationship between AOM and AIT derived using this type of quasi-experimental design, and therefore it would appear appropriate to state that the age of menarche in athletes is "later" rather than "delayed".
基于回顾性数据以及准实验设计的研究得出结论，青春期前的体育训练可能会使月经初潮延迟。此外，有人提出训练起始年龄（AIT）与月经初潮年龄（AOM）之间存在因果关系。为了研究这些结论是否错误以及是否基于分析假象，使用一个计算机程序为30000名“运动员”群体生成随机且独立的AOM和AIT。生成的平均AOM（均值 = 13.4岁）和平均AIT（均值 = 10.0岁）与近期文献报道的相似。抽样程序设计为在这些假设的运动员中AOM和AIT之间不存在关系（r = 0.002）。当比较两个亚组（月经初潮前或月经初潮后训练）时，发现训练前组的AOM显著晚于训练后组（均值分别为13.9岁和11.7岁；P < 0.05）。在每个亚组中都发现AOM和AIT之间存在显著相关性（月经初潮前和月经初潮后训练的r分别为0.46和0.40），与先前报道的值相似。总之，本研究以及类似数据集中所执行的抽样程序会导致对统计参数的估计产生偏差。这种偏差解释了使用此类准实验设计得出的AOM和AIT之间的报道关系，因此似乎可以恰当地说运动员的月经初潮年龄是“较晚”而非“延迟”。
