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Fragility index of urological literature regarding medical expulsive treatment

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Abstract

Introduction

The role of medical expulsive treatment (MET) is controversial. Fragility index is an additional metric to assess randomized controlled trials (RCTs) outcome validity and indicates how many patients would be required to convert a trial from being statistically significant, to not significant. The larger is the FI, the better the trial’s data. The aim of this study is to assess FI of RCTs regarding MET for ureteral stones.

Materials and methods

A systematic literature search was performed. RCTs, reporting stone expulsion as a dichotomous outcome, showing statistical significance were eligible. FI (the number of patients needed to change from a non-event to event group, to lose statistical significance) and Fragility quotient (FI divided by total sample size), were calculated while Pearson’s correlation and Mann–Whitney U test were used as appropriate.

Results

Thirty-six RCTs were eligible, with median FI = 3.5 and fragility quotient = 0.042, median sample size = 81, median journal impact factor = 1.73 and median reported p value = 0.008. In 33.3% of the studies, number of patients lost during follow-up was larger than FI, while in 13.89% of the studies, FI was 0, indicating use of inappropriate statistical method. Pearson’s correlation showed significant positive association between FI and sample size (r = 0.981), number of events (r = 0.982) and impact factor (r = 0.731), while no association was found with p value or publication year.

Conclusions

In this analysis, a calculated FI of 3.5 indicates that findings from RCTs on MET for ureteral stones are fragile and should be interpreted in combination with clinical thinking and expertise.

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References

  1. Turney BW, Reynard JM, Noble JG, Keoghane SR (2012) Trends in urological stone disease. BJU Int 109(7):1082–1087

    Article  Google Scholar 

  2. Türk C, Petřík A, Sarica K, Seitz C, Skolarikos A, Straub M et al (2016) EAU guidelines on diagnosis and conservative management of urolithiasis. Eur Urol 69(3):468–474

    Article  Google Scholar 

  3. Türk C, Petřík A, Sarica K, Seitz C, Skolarikos A, Straub M et al (2016) EAU guidelines on interventional treatment for urolithiasis. Eur Urol 69(3):475–482

    Article  Google Scholar 

  4. Mourmouris P, Tzelves L, Skolarikos A (2020) Complications after active stone removal. Curr Opin Urol 30(2):135–143

    Article  Google Scholar 

  5. Vassileva J, Zagorska A, Basic D, Karagiannis A, Petkova K, Sabuncu K et al (2020) Radiation exposure of patients during endourological procedures: IAEA-SEGUR study. J Radiol Protect 40(4):1390–1405

    Article  Google Scholar 

  6. Vassileva J, Zagorska A, Karagiannis A, Petkova K, Sabuncu K, Saltirov I et al (2020) Radiation exposure of surgical team during endourological procedures: International Atomic Energy Agency-South-Eastern European Group for Urolithiasis Research Study. J Endourol. (Online Ahead of Print)

  7. Pearle MS, Goldfarb DS, Assimos DG, Curhan G, Denu-Ciocca CJ, Matlaga BR et al (2014) Medical management of kidney stones: AUA guideline. J Urol 192(2):316–324

    Article  Google Scholar 

  8. Tzelves L, Mourmouris P, Skolarikos A (2021) Comparison of current guidelines on medical management of stone disease. Arch Esp Urol 74(1):171–182

    PubMed  Google Scholar 

  9. Campschroer T, Zhu X, Vernooij RWM, Lock T (2018) α-blockers as medical expulsive therapy for ureteric stones: a Cochrane systematic review. BJU Int 122(6):932–945

    Article  CAS  Google Scholar 

  10. Hollingsworth JM, Canales BK, Rogers MA, Sukumar S, Yan P, Kuntz GM et al (2016) Alpha blockers for treatment of ureteric stones: systematic review and meta-analysis. BMJ (Clinical research ed) 355:i6112

    Google Scholar 

  11. Türk C, Knoll T, Petřík A, Sarica K, Seitz C, Skolarikos A (2017) Grey Zones in Urolithiasis Guidelines. Eur Urol Focus 3(1):144–146

    Article  Google Scholar 

  12. Tzelves L, Türk C, Skolarikos A (2021) European Association of Urology Urolithiasis Guidelines: Where Are We Going? Eur Urol Focus 7(1):34–38

    Article  Google Scholar 

  13. Pickard R, Starr K, MacLennan G, Lam T, Thomas R, Burr J et al (2015) Medical expulsive therapy in adults with ureteric colic: a multicentre, randomised, placebo-controlled trial. The Lancet 386(9991):341–349

    Article  Google Scholar 

  14. Sur RL, Shore N, L’Esperance J, Knudsen B, Gupta M, Olsen S et al (2015) Silodosin to facilitate passage of ureteral stones: a multi-institutional, randomized, double-blinded, placebo-controlled trial. Eur Urol 67(5):959–964

    Article  CAS  Google Scholar 

  15. Skolarikos A, Ghani KR, Seitz C, Van Asseldonk B, Bultitude MF (2017) Medical expulsive therapy in urolithiasis: a review of the quality of the current evidence. Eur Urol Focus 3(1):27–45

    Article  Google Scholar 

  16. Higgins JP, Altman DG, Gøtzsche PC, Jüni P, Moher D, Oxman AD et al (2011) The Cochrane Collaboration’s tool for assessing risk of bias in randomised trials. BMJ (Clinical research ed) 343:d5928

    Article  Google Scholar 

  17. Walsh M, Srinathan SK, McAuley DF, Mrkobrada M, Levine O, Ribic C et al (2014) The statistical significance of randomized controlled trial results is frequently fragile: a case for a Fragility Index. J Clin Epidemiol 67(6):622–628

    Article  Google Scholar 

  18. Narayan VM, Gandhi S, Chrouser K, Evaniew N, Dahm P (2018) The fragility of statistically significant findings from randomised controlled trials in the urological literature. BJU Int 122(1):160–166

    Article  Google Scholar 

  19. Rickard M, Lorenzo AJ, Hannick JH, Blais AS, Koyle MA, Bägli DJ (2019) Over-reliance on P values in urology: fragility of findings in the hydronephrosis literature calls for systematic reporting of robustness indicators. Urology 133:204–210

    Article  Google Scholar 

  20. Khan MS, Ochani RK, Shaikh A, Usman MS, Yamani N, Khan SU et al (2019) Fragility index in cardiovascular randomized controlled trials. Circ Cardiovasc Qual Outcomes. 12(12):e005755

    Article  Google Scholar 

  21. Farland LV, Correia KF, Wise LA, Williams PL, Ginsburg ES, Missmer SA (2016) P-values and reproductive health: what can clinical researchers learn from the American Statistical Association? Human Reprod (Oxford, England) 31(11):2406–2410

    Article  CAS  Google Scholar 

  22. Thorlund K, Imberger G, Walsh M, Chu R, Gluud C, Wetterslev J et al (2011) The number of patients and events required to limit the risk of overestimation of intervention effects in meta-analysis—a simulation study. PLoS ONE 6(10):e25491-e

    Article  Google Scholar 

  23. Majeed M, Agrawal R, Attar BM, Kamal S, Patel P, Omar YA et al (2020) Fragility index: how fragile is the data that support the American College of Gastroenterology guidelines for the management of Crohn’s disease? Eur J Gastroenterol Hepatol 32(2):193–198

    Article  Google Scholar 

  24. Shochet LR, Kerr PG, Polkinghorne KR (2017) The fragility of significant results underscores the need of larger randomized controlled trials in nephrology. Kidney Int 92(6):1469–1475

    Article  Google Scholar 

  25. Evaniew N, Files C, Smith C, Bhandari M, Ghert M, Walsh M et al (2015) The fragility of statistically significant findings from randomized trials in spine surgery: a systematic survey. Spine J 15(10):2188–2197

    Article  Google Scholar 

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Authors and Affiliations

  1. Second Department of Urology, Sismanogleio General Hospital, National and Kapodistrian University of Athens, Athens, Greece

    Lazaros Tzelves, Nikolaos Chatzikrachtis, Lazaros Lazarou, Panagiotis Mourmouris, Alexandros Pinitas, Kimon Tsirkas, Orestis Petropoulos, Marinos Berdempes, Ioannis Varkarakis & Andreas Skolarikos

  2. Department of Quality Control, Research and Continuing Education, Sismanogleio General Hospital, 15126, Marousi, Greece

    Georgios Feretzakis

  3. Department of Urology, General Hospital of Athens “G. Gennimatas”, Athens, Greece

    Ioannis Glykas & Charalampos Fragkoulis

Authors
  1. Lazaros Tzelves
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  2. Nikolaos Chatzikrachtis
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  3. Lazaros Lazarou
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  4. Panagiotis Mourmouris
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  5. Alexandros Pinitas
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  6. Kimon Tsirkas
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  8. Marinos Berdempes
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  10. Ioannis Glykas
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  11. Charalampos Fragkoulis
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  12. Ioannis Varkarakis
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  13. Andreas Skolarikos
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Correspondence to Ioannis Glykas.

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Tzelves, L., Chatzikrachtis, N., Lazarou, L. et al. Fragility index of urological literature regarding medical expulsive treatment. World J Urol 39, 3741–3746 (2021). https://doi.org/10.1007/s00345-021-03725-2

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  • DOI: https://doi.org/10.1007/s00345-021-03725-2

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