Department of Intensive Care Medicine, Royal Perth Hospital, Perth, WA 6000, Australia.
Br J Anaesth. 2011 Apr;106(4):528-36. doi: 10.1093/bja/aeq417. Epub 2011 Feb 19.
The role of corticosteroids in severe sepsis and pneumonia remains controversial. This study described the use of L'Abbé and pooled calibration plots to assess the relationship between severity of illness and effectiveness of corticosteroids for severe sepsis.
Randomized controlled trials (RCTs) comparing corticosteroids and placebo from Cochrane Controlled Trial Register, MEDLINE, and EMBASE databases were retrieved. The observed and predicted mortality rates of the placebo groups were used as a measure of the severity of illness of the patients in L'Abbé and calibration plots.
A total of 1089 patients from 10 RCTs fulfilled the inclusion criteria and were subject to further analysis. L'Abbé and calibration plots did not suggest significant interactions between the effectiveness of corticosteroids and severity of illness. The pooled calibration plot suggested that the mortality rates of the placebo groups from three studies were higher than predicted. After excluding these studies in the meta-analysis, there was a reduction in the point estimate of benefit of corticosteroids on mortality [odds ratio (OR) 0.97, 95% confidence interval (CI): 0.71-1.33, P=0.87 by a fixed-effect model, P=0.59 by a random-effects model vs OR 0.85, 95% CI: 0.66-1.10%].
The pooled calibration plot suggested that there were excessive deaths in the placebo groups of some RCTs that could explain the apparent benefit of corticosteroids on mortality of patients with severe sepsis. L'Abbé and pooled calibration plots might be useful as adjuncts to assess interactions between severity of illness and effectiveness of an intervention.
皮质类固醇在严重脓毒症和肺炎中的作用仍存在争议。本研究通过描述 L'Abbé 和汇总校准图来评估皮质类固醇治疗严重脓毒症的严重程度和疗效之间的关系。
从 Cochrane 对照试验注册中心、MEDLINE 和 EMBASE 数据库中检索了比较皮质类固醇和安慰剂的随机对照试验（RCT）。安慰剂组的观察死亡率和预测死亡率被用作 L'Abbé 和校准图中患者严重程度的衡量标准。
共有 10 项 RCT 的 1089 名患者符合纳入标准，并进行了进一步分析。L'Abbé 和校准图并未提示皮质类固醇的疗效与严重程度之间存在显著的交互作用。汇总校准图提示，来自三项研究的安慰剂组的死亡率高于预测。在荟萃分析中排除这些研究后，皮质类固醇对死亡率的益处的点估计值降低[比值比（OR）0.97，95%置信区间（CI）：0.71-1.33，P=0.87 采用固定效应模型，P=0.59 采用随机效应模型与 OR 0.85，95%CI：0.66-1.10%]。
汇总校准图提示，一些 RCT 中的安慰剂组出现了过多的死亡，这可能解释了皮质类固醇对严重脓毒症患者死亡率的明显益处。L'Abbé 和汇总校准图可作为评估干预措施严重程度和疗效之间相互作用的辅助手段。
