From the Department of Anesthesiology, University of Virginia, Charlottesville, Virginia (A.S.T., M.T.); Department of Anesthesiology, King Fahad Medical City, Riyadh, Saudi Arabia (A.S.T.); Outcomes Research Consortium, Cleveland Clinic, Cleveland, Ohio (A.S.T.); Departments of Primary School Education and Hygiene and Epidemiology, University of Ioannina, Epirus, Greece (D.M.); Department of Anesthesiology Perioperative and Pain Medicine, Stanford University, Stanford, California (P.F.); Copenhagen Trial Unit, Centre for Clinical Intervention Research, Copenhagen, Denmark (J.W.); Children Hospital, King Fahad Medical City, Riyadh, Saudi Arabia (R.S.T.); Department of Internal Medicine, Cardiovascular disease section, University of Iowa Hospitals and Clinics, Iowa City, Iowa (A.A.B.A.); and Claude Moore Health Sciences Library, University of Virginia, Charlottesville, Virginia (M.S.N.).
Anesthesiology. 2016 Apr;124(4):846-69. doi: 10.1097/ALN.0000000000001039.
Disagreement among many underpowered studies has led to an equivocal understanding of the efficacy of the 5-HT3 antagonist ondansetron in preventing the consequences of sympathectomy after subarachnoid anesthesia. The authors assessed the efficacy of ondansetron with respect to the overall quality and statistical power of the meta-analyses.
The authors used a standard and a newer method of meta-analysis, trial sequential analysis (TSA), to estimate adjusted CIs based on how much information has been accrued. They also used random-effects meta-analyses techniques, small trial bias assessment, selection models, sensitivity analyses, and the Grading of Recommendations on Assessment, Development, and Evaluation system. These results from the aforementioned techniques were compared, and importance of consideration of these factors was discussed.
Fourteen randomized placebo-controlled trials (1,045 subjects) were identified and analyzed. By using conventional meta-analyses, the authors determined that ondansetron was associated with reduction in the incidence of hypotension (relative risk = 0.62 [95% CI, 0.46 to 0.83], P = 0.001; TSA-adjusted CI, 0.34 to 1.12; I = 60%, P = 0.002) and bradycardia (relative risk = 0.44 [95% CI, 0.26 to 0.73], P = 0.001; TSA-adjusted CI, 0.05 to 3.85; I = 0%, P = 0.84). However, the authors found indications of bias among these trials. TSAs demonstrated that the meta-analysis lacked adequate information size and did not achieve statistical significance when adjusted for sparse data and repetitive testing. The Grading of Recommendations on Assessment, Development, and Evaluation system showed that the results had low to very low quality of evidence.
The analyses fail to confirm evidence that ondansetron reduces the incidence of hypotension and bradycardia after subarachnoid anesthesia due to the risk of bias and information sizes less than the required. As results from meta-analysis are given significant weight, it is important to carefully evaluate the quality of the evidence that is input.
许多研究的效力不足导致人们对 5-HT3 拮抗剂昂丹司琼在预防蛛网膜下腔麻醉后交感神经切除的后果方面的疗效存在争议。作者评估了昂丹司琼的疗效，同时考虑了荟萃分析的整体质量和统计效力。
作者使用标准和更新的荟萃分析方法，即试验序贯分析（TSA），根据累积信息量来估计调整后的置信区间。他们还使用了随机效应荟萃分析技术、小试验偏倚评估、选择模型、敏感性分析和推荐评估、发展和评估系统的分级。比较了上述技术的结果，并讨论了考虑这些因素的重要性。
确定并分析了 14 项随机安慰剂对照试验（1045 例患者）。通过使用常规荟萃分析，作者确定昂丹司琼与降低低血压（相对风险=0.62 [95%置信区间，0.46 至 0.83]，P=0.001；TSA 调整后的置信区间，0.34 至 1.12；I=60%，P=0.002）和心动过缓（相对风险=0.44 [95%置信区间，0.26 至 0.73]，P=0.001；TSA 调整后的置信区间，0.05 至 3.85；I=0%，P=0.84）的发生率有关。然而，作者发现这些试验存在偏倚的迹象。TSA 表明，荟萃分析缺乏足够的信息大小，并且在调整稀疏数据和重复测试时未达到统计学意义。推荐评估、发展和评估系统的分级显示，结果的证据质量为低至非常低。
由于存在偏倚风险和信息大小小于要求，分析未能证实昂丹司琼可降低蛛网膜下腔麻醉后低血压和心动过缓的发生率。由于荟萃分析的结果具有重要意义，因此输入的证据质量需要仔细评估。
