INSERM, U738, Paris, France.
Br J Anaesth. 2013 Dec;111(6):897-906. doi: 10.1093/bja/aet250. Epub 2013 Jul 19.
Heterogeneity and its causes must be assessed using meta-analyses (meta-analysis). Especially in meta-analysis dealing with treatment of acute postoperative pain, the type of surgery is a source of heterogeneity. We aimed to assess whether the type of surgery is considered a source of heterogeneity in meta-analysis and how it is taken into account in meta-analysis evaluating the efficacy of treatment of acute postoperative pain. We further compared meta-analysis that pooled trials of surgeries with highly heterogeneous postoperative pain levels, the heterogeneous group, with meta-analysis that pooled trials involving surgeries with homogeneous pain levels, the homogenous group.
The meta-analysis reports available in Issue 3, 2011 of the electronic database of the Cochrane library and pooling results of randomized or quasi-randomized controlled trials that assessed the efficacy of treatment of acute postoperative pain alone were considered. A survey of experts established a rating of the postoperative pain levels for the type of surgery. For each meta-analysis, the different pain level ratings associated with the trials included in the meta-analysis were considered and the standard deviation (sd) of these ratings calculated. From the distribution of sd values, we defined the heterogeneous and homogeneous groups.
Sixty-one meta-analyses were included; all assessed heterogeneity. Twenty-six meta-analyses considered the type of surgery as a subgroup (50% vs 38% in the homogeneous group vs heterogeneous group). Forty-four reports discussed the type of surgery as a source of clinical heterogeneity (85% vs 62% for the homogeneous vs heterogeneous group). Twenty-nine meta-analyses compared 'postoperative pain from dental surgery' to 'other type of surgery'.
Meta-analyses evaluating treatment of postoperative pain should explore clinical heterogeneity associated with the type of surgery for better implications for practice.
使用荟萃分析（meta-analysis）必须评估异质性及其原因。特别是在处理急性术后疼痛的治疗荟萃分析中，手术类型是异质性的来源。我们旨在评估手术类型是否被认为是荟萃分析中的异质性来源，以及在评估急性术后疼痛治疗效果的荟萃分析中如何考虑手术类型。我们进一步比较了荟萃分析，该分析汇总了具有高度异质术后疼痛水平的手术试验，即异质组，与汇总具有同质疼痛水平的手术试验的荟萃分析，即同质组。
考虑了在 2011 年 3 月版 Cochrane 电子数据库中可获得的荟萃分析报告，并汇总了单独评估急性术后疼痛治疗效果的随机或半随机对照试验的结果。专家调查确定了手术类型的术后疼痛水平评分。对于每个荟萃分析，都考虑了与荟萃分析中包含的试验相关的不同疼痛水平评分，并计算了这些评分的标准差（sd）。根据 sd 值的分布，我们定义了异质组和同质组。
共纳入 61 项荟萃分析；所有分析均评估了异质性。26 项荟萃分析将手术类型视为亚组（同质组为 50%，异质组为 38%）。44 项报告将手术类型讨论为临床异质性的来源（同质组为 85%，异质组为 62%）。29 项荟萃分析将“牙科手术后的疼痛”与“其他类型的手术”进行了比较。
评估术后疼痛治疗的荟萃分析应探讨与手术类型相关的临床异质性，以便更好地为实践提供指导。
