Fernandes Ricardo, Ferreira Joaquim J, Sampaio Cristina
Pediatrics Department, Santa Maria Hospital, Lisbon, Portugal.
J Pediatr. 2008 Apr;152(4):527-33, 533.e1. doi: 10.1016/j.jpeds.2007.09.024. Epub 2007 Dec 3.
To characterize the magnitude of the placebo response in trials of migraine therapy in children and adolescents, and to identify its determinants.
MEDLINE and CENTRAL were searched through November 2006 for randomized controlled trials or controlled clinical trials of pediatric acute migraine pharmacologic treatment that included a placebo comparator group. The main outcomes were headache relief and pain-free response, and effect estimates for risk differences were calculated whenever possible. The influence of placebo response determinants was studied using subgroup analysis. A total of 13 trials (1324 participants in the placebo groups) were included in the analysis.
The pooled placebo responses for pain relief and pain-free at 2 hours were 46% (range, 38% to 53%) and 21% (range, 17% to 26%). Parallel studies conducted in North American centers demonstrated a significantly higher placebo response, as did trials that used 4-point pain scales. Other placebo determinants did not influence the effect estimate, although insufficient data were available to study some of them.
There is a widely variable placebo response in pediatric migraine trials, supporting the continued use of placebo groups and suggesting the need for more research into the placebo effect in the pediatric population.
描述儿童和青少年偏头痛治疗试验中安慰剂反应的程度，并确定其决定因素。
检索MEDLINE和CENTRAL数据库至2006年11月，查找儿科急性偏头痛药物治疗的随机对照试验或对照临床试验，这些试验需包含安慰剂对照分组。主要结局为头痛缓解和无痛反应，并尽可能计算风险差异的效应估计值。使用亚组分析研究安慰剂反应决定因素的影响。分析共纳入13项试验（安慰剂组有1324名参与者）。
2小时时疼痛缓解和无痛的合并安慰剂反应分别为46%（范围38%至53%）和21%（范围17%至26%）。在北美中心进行的平行研究显示安慰剂反应显著更高，使用4分制疼痛量表的试验也是如此。其他安慰剂决定因素未影响效应估计值，不过研究其中一些因素的数据不足。
儿科偏头痛试验中的安慰剂反应差异很大，这支持继续使用安慰剂组，并表明需要对儿科人群中的安慰剂效应进行更多研究。
