J-shapedness: an often missed, often miscalculated relation: the example of weight and mortality
J-shapedness: an often missed, often miscalculated relation: the example of weight and mortality
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DOI：
10.1136/jech-2013-203439
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发表时间：
2014-07-01
影响因子：
6.3
通讯作者：
Ray, Joel G.
中科院分区：
文献类型：
--
作者：
Cao, Sissi;Moineddin, Rahim;Ray, Joel G.
我们提出了三个考虑因素，在分析体重和死亡率之间的关联，以及其他关系，可能是非线性的性质。首先，作者必须以连续的方式用图形绘制他们的自变量和因变量。其次，作者应该评估这种关系的形态，并注意它的形态。如果它是非线性的，特别是J形或U形，则应仔细考虑使用"最佳"统计模型，其中多元分数多项式回归是一个合理的选择。作者还应避免截断数据，以避免处理非线性关系。
We present three considerations in analysing the association between weight and mortality, as well as other relations that might be non-linear in nature. First, authors must graphically plot their independent and dependent variables in a continuous manner. Second, authors should assess the shape of that relation, and note its shape. If it is non-linear, and specifically, J-shaped or U-shaped, careful consideration should be given to using the `best' statistical model, of which multivariate fractional polynomial regression is a reasonable choice. Authors should also refrain from truncating their data to avoid dealing with non-linear relations.