INTRACLASS CORRELATION AMONG COMMON MEASURES OF ADOLESCENT SMOKING - ESTIMATES, CORRELATES, AND APPLICATIONS IN SMOKING PREVENTION STUDIES
INTRACLASS CORRELATION AMONG COMMON MEASURES OF ADOLESCENT SMOKING - ESTIMATES, CORRELATES, AND APPLICATIONS IN SMOKING PREVENTION STUDIES
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DOI：
10.1093/oxfordjournals.aje.a117194
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发表时间：
1994-12-01
影响因子：
5
通讯作者：
SCHINKE, SP
中科院分区：
文献类型：
--
作者：
MURRAY, DM;ROONEY, BL;SCHINKE, SP
大多数青少年吸烟预防研究采用的设计，其中教室，学校，学区，有时整个社区被分配到治疗条件，而对个别学生进行观察。这种社区试验的关键设计特征是在处理条件下嵌套完整的社会群体。这种组合要求根据组间方差评估治疗效果;不幸的是，该方差通常大于随机组成的组，其精密度通常低于组内方差。这些因素通常联合收割机降低功率，因此在设计良好且执行适当的研究中几乎不可能检测到重要的治疗效果。为了解决这些问题，研究人员需要对感兴趣的变量的组内相关性进行良好的估计，这与每个单位的观测数量一起确定嵌套设计中额外变异的大小。本文的目的是描述的方法和结果的研究，旨在产生估计组内相关的青少年吸烟预防研究的共同成果，并讨论使用这些估计在规划新的研究。
Most adolescent smoking prevention studies employ designs in which classrooms, schools, school districts, or sometimes whole communities are assigned to treatment conditions while observations are made on individual students. The critical design feature in such community trials is the nesting of intact social groups within treatment conditions. This combination requires that the treatment effect be assessed against the between-group variance; unfortunately, that variance is usually larger than for randomly constituted groups and its precision is usually less than that for the within-group variance. These factors often combine to reduce power so that it is almost impossible to detect important treatment effects in an otherwise well designed and properly executed study. To address these problems, investigators need good estimates of the intraclass correlation for the variables of interest, which together with the number of observations per unit determine the magnitude of the extra variation in the nested design. The purpose of this paper is to describe the methods and results from a study designed to generate estimates of intraclass correlation for common outcomes in adolescent smoking prevention studies and to discuss the use of these estimates in the planning of new studies.