Shokraneh Farhad, Adams Clive E
Cochrane Schizophrenia Group, Division of Psychiatry and Applied Psychology, Institute of Mental Health, School of Medicine, University of Nottingham, Nottingham, NG7 2TU, UK.
F1000Res. 2019 Jan 9;8:38. doi: 10.12688/f1000research.17352.2. eCollection 2019.
We present use of a simple formula to calculate the number of pairwise comparisons of interventions within a single trial or network meta-analyses. We used the data from our previous network meta-analysis to build a study-based register and enumerated the direct pairwise comparisons from the trials therein. We then compared this with the number of comparisons predicted by use of the formula and finally with the reported number of comparisons (indirect or direct) within the network meta-analysis. A total of 133 trials of 8 interventions were selected which included 163 comparisons. The network of these showed 16 unique direct comparisons. The formula predicted an expected 28 indirect or direct comparisons and this is the number that were indeed reported. The formula produces an accurate enumeration of the potential comparisons within a single trial or network meta-analysis. Its use could help transparency of reporting should a shortfall occur between comparisons actually used and the potential total.
我们介绍了一种简单公式的用法，用于计算单个试验或网络荟萃分析中干预措施的成对比较数量。我们使用之前网络荟萃分析的数据建立了一个基于研究的登记册，并列举了其中试验的直接成对比较。然后，我们将其与使用该公式预测的比较数量进行比较，最后与网络荟萃分析中报告的比较数量（间接或直接）进行比较。总共选择了8种干预措施的133项试验，其中包括163项比较。这些试验的网络显示有16种独特的直接比较。该公式预测有28项预期的间接或直接比较，而实际报告的正是这个数量。该公式能准确计算单个试验或网络荟萃分析中的潜在比较数量。如果实际使用的比较与潜在总数之间出现差距，使用该公式有助于提高报告的透明度。
