Klinik für Kinder- und Jugendmedizin, Klinikum Dortmund, Dortmund, Germany.
Kinderchirurgische Klinik und Poliklinik im Dr. von Haunerschen Kinderspital, Ludwig-Maximilians-Universität München, München, Germany.
Pediatr Surg Int. 2022 Jul;38(7):1057-1066. doi: 10.1007/s00383-022-05133-y. Epub 2022 May 7.
The fragility index has been gaining ground in the evaluation of comparative clinical studies. Many scientists evaluated trials in their fields and deemed them to be fragile, although there is no consensus on the definition of fragility. We aimed to calculate the fragility index and its permutations for paediatric surgical trials.
We searched pubmed for prospectively conducted paediatric surgical trials with intervention and control group without limitations and calculated their (reverse) fragility indices and respective quotients along with posthoc-power. Relationships between variables were evaluated using Spearman's ρ. We also calculated S values by negative log transformation base-2 of P values.
Of 516 retrieved records, we included 87. The median fragility index was 1.5 (interquartile range: 0-4) and the median reverse fragility index was 3 (interquartile range: 2-4), although they were statistically not different (Mood's test: χ = 0.557, df = 1, P = 0.4556). P values and fragility indices were strongly inversely correlated (ρ = - 0.71, 95% confidence interval: - 0.53 to - 0.85, P < 0.0001), while reverse fragility indices were moderately correlated to P values (ρ = 0.5, 95% confidence interval: 0.37-0.62, P < 0.0001). A fragility index of 1 resulted from P values between 0.039 and 0.003, which resulted in S values between 4 and 8.
Fragility indices, reverse fragility indices, and their respective fragility quotients of paediatric surgical trials are low. The fragility index can be viewed as no more than a transformed P value with even more substantial limitations. Its inherent penalisation of small studies irrespective of their clinical relevance is particularly harmful for paediatric surgery. Consequently, the fragility index should be avoided.
脆弱指数在评估临床对照研究方面越来越受到重视。许多科学家对其所在领域的试验进行了评估，认为这些试验是脆弱的，尽管对于脆弱性的定义还没有达成共识。我们旨在计算儿科外科试验的脆弱指数及其排列。
我们在 pubmed 上搜索了没有限制的前瞻性儿科外科试验，包括干预组和对照组，并计算了它们的（反向）脆弱指数及其相应的脆弱指数比值以及事后功效。使用 Spearman's ρ 评估变量之间的关系。我们还通过将 P 值的负对数转换为以 2 为底的 S 值来计算 S 值。
在检索到的 516 条记录中，我们纳入了 87 条记录。中位数脆弱指数为 1.5（四分位间距：0-4），中位数反向脆弱指数为 3（四分位间距：2-4），尽管两者在统计学上无差异（Mood's 检验：χ=0.557，df=1，P=0.4556）。P 值与脆弱指数呈强烈的负相关（ρ=-0.71，95%置信区间：-0.53 至-0.85，P<0.0001），而反向脆弱指数与 P 值中度相关（ρ=0.5，95%置信区间：0.37-0.62，P<0.0001）。脆弱指数为 1 时，P 值在 0.039 和 0.003 之间，这导致 S 值在 4 和 8 之间。
儿科外科试验的脆弱指数、反向脆弱指数及其各自的脆弱指数比值均较低。脆弱指数可以被视为仅仅是一个经过转换的 P 值，而且具有更多的限制。它对小研究的固有惩罚，无论其临床相关性如何，对儿科外科都特别有害。因此，应该避免使用脆弱指数。
