Understanding the relationship between baseline BMI and subsequent weight change in antipsychotic trials: Effect modification or regression to the mean?
Understanding the relationship between baseline BMI and subsequent weight change in antipsychotic trials: Effect modification or regression to the mean?
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DOI：
10.1016/j.psychres.2008.10.007
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发表时间：
2009-12-30
影响因子：
11.3
通讯作者：
Siu, Cynthia O.
中科院分区：
文献类型：
--
作者：
Allison, David B.;Loebel, Antony D.;Siu, Cynthia O.
本研究的目的是检查初始体重与后续抗精神病药诱导的体重变化之间呈反比关系的既往证据是否代表真实效应改变或统计学伪影，即回归平均值（RTM）。我们对齐拉西酮和其他抗精神病药物的7项随机、安慰剂或活性对照试验进行了事后分析。采用ANCOVA评价治疗与基线体重指数（BMI）范围对体重变化的相互作用效应。应用回归分析估计RTM引起的潜在偏倚。基线BMI范围和治疗分配（氟哌啶醇、奥氮平）之间的统计学相互作用检验。利培酮或齐拉西酮与安慰剂相比）在研究内或研究间均不显著。安慰剂治疗受试者的基线和随访体重测量值之间的相关性不太理想（r = 0.87）。6-月队列），导致RTM。与基于RTM的预测一致，平均而言，在基线体重与群体平均值差异最大的亚组中观察到最大的体重变化。我们的研究结果表明，先前观察到的基线BMI和抗精神病药物治疗后体重变化之间的相关性部分反映了RTM，而不是效应修正。这类药物似乎在高和低基线BMI组中引起相似的体重增加。(C)2008爱思唯尔爱尔兰有限公司保留所有权利。
The purpose of this study was to examine whether prior evidence of an inverse relationship between initial body weight and subsequent antipsychotic-induced weight change represents true effect modification or a statistical artifact, regression to the mean (RTM). We conducted a post-hoc analysis after pooling seven randomized, placebo- or active-controlled trials of ziprasidone and other antipsychotic agents. ANCOVA was applied to evaluate treatment-by-baseline body mass index (BMI) range interaction effect on weight change. Regression analysis was applied to estimate the potential bias due to RTM. Statistical interaction tests between baseline BMI ranges and treatment assignments (haloperidol, olanzapine. risperidone, or ziprasidone, versus placebo) were not significant within studies or across studies. Correlation between baseline and follow-up measurements of body weight in placebo-treated subjects was less than perfect (r = 0.87. 6-month cohort), leading to RTM. Consistent with predictions based on RTM, the greatest weight change, on average, was observed in subgroups with baseline weights differing the most from the population mean. Our findings suggest that the previously observed correlation between baseline BMI and weight change subsequent to antipsychotic treatment reflects in part RTM, and not effect modification. This class of drugs appears to cause similar weight gain in both high and low baseline BMI groups. (C) 2008 Elsevier Ireland Ltd. All rights reserved.