Division of Urology, Hospital for Sick Children and Department of Surgery, University of Toronto, Toronto, Ontario, Canada.
Division of Urology, Hospital for Sick Children and Department of Surgery, University of Toronto, Toronto, Ontario, Canada.
Urology. 2019 Nov;133:204-210. doi: 10.1016/j.urology.2019.03.045. Epub 2019 Jul 30.
To review the robustness of hydronephrosis literature with the application of fragility index (FI) and fragility quotient (FQ) calculations.
A literature review was conducted using Pubmed, Medline, and Ovid for "hydronephrosis" and associated terms and we included all studies with at least 2 groups being compared. FI was calculated by populating study results into a 2-by-2 contingency table and generating a P value using Fisher's exact test. Next, events were manually added to the group with the fewest events, while removing a nonevent from the same group and Fisher's exact test repeated until the P value was >.05. FQ was calculated by dividing FI by the total sample size.
The 130 included articles were published between 1986 and 2018 in 32 journals. Median citation count was 14 (0-252), 30% were RCTs and most papers originated in the United States (28%), Turkey(10%), and Canada(9%). Median FI was 2 (1-112), FQ was 0.023 (0.0010-0.55), and 60 papers (46%) had a FI of 1, indicating extremely fragile results. There was a significant difference in the FI between observational studies and RCTs (10 ± 17 vs 4 ± 5; P = .02); however, there was no difference in FQ (0.032 ± 0.030 vs 0.053 ± 0.080; P = .09) between them.
Nearly half of studies in hydronephrosis literature reporting significant results are extremely fragile, requiring addition of only a couple of events in 1 treatment arm to significantly modify the results. As such, objective reporting of robustness of results should include FI and FQ which may help diminish over-reliance on P values as the main indicator of clinical significance in comparative studies.
应用脆弱指数（FI）和脆弱分数（FQ）计算来回顾肾积水文献的稳健性。
使用 Pubmed、Medline 和 Ovid 对“肾积水”及其相关术语进行文献回顾，并纳入至少有 2 组比较的所有研究。通过将研究结果填入 2×2 列联表并使用 Fisher 精确检验生成 P 值来计算 FI。接下来，将事件手动添加到事件数最少的组中，同时从同一组中删除一个非事件，并重复 Fisher 精确检验，直到 P 值大于 0.05。FQ 通过将 FI 除以总样本量来计算。
纳入的 130 篇文章发表于 1986 年至 2018 年，发表于 32 种期刊上。中位数引用数为 14（0-252），30%为 RCT，大多数论文来自美国（28%）、土耳其（10%）和加拿大（9%）。中位数 FI 为 2（1-112），FQ 为 0.023（0.0010-0.55），60 篇（46%）的 FI 为 1，表明结果极其脆弱。观察性研究和 RCT 的 FI 差异有统计学意义（10±17 与 4±5；P=0.02）；然而，两者的 FQ 差异无统计学意义（0.032±0.030 与 0.053±0.080；P=0.09）。
肾积水文献中近一半报告阳性结果的研究极其脆弱，只需在 1 个治疗组中增加几个事件即可显著改变结果。因此，客观报告结果的稳健性应包括 FI 和 FQ，这可能有助于减少对 P 值作为比较研究中临床意义主要指标的过度依赖。
