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Fragility of Statistically Significant Outcomes in Colonic Diverticular Disease Randomized Trials: A Systematic
Tyler McKechnie1, Shuling Yang2, Kathy Wu2
1Division of General Surgery, Department of Surgery, McMaster University, Hamilton, Ontario, Canada.
Background:
The p value has been criticized as an oversimplified determination of whether a treatment effect exists. One alternative is the fragility index. It is a representation of the minimum number of nonevents that would need to be converted to events to increase the p value above 0.05.
Objective:
To determine the fragility index of randomized controlled trials assessing the efficacy of interventions for patients with diverticular disease since 2010 to assess the robustness of current evidence.
Design:
MEDLINE, Embase, and Cochrane Central Register of Controlled Trials were searched from inception to August 2022.
Settings:
Articles were eligible for inclusion if they were randomized trials conducted between 2010 and 2022 with parallel, superiority designs evaluating interventions in patients with diverticular disease. Only randomized trials with dichotomous primary outcomes with an associated p value of <0.05 were considered for inclusion.
Participants:
Any surgical or medical intervention for patients with diverticular disease.
Main Outcome Measures:
The fragility index was determined by adding events and subtracting nonevents from the groups with the smaller number of events. Events were added until the p value exceeded 0.05. The smallest number of events required was considered the fragility index.
Results:
After screening 1271 citations, 15 randomized trials met the inclusion criteria. Nine of the studies evaluated surgical interventions and 6 evaluated medical interventions. The mean number of patients randomly assigned and lost to follow-up per randomized controlled trial was 92 (SD 35.3) and 9 (SD 11.4), respectively. The median fragility index was 1 (range, 0-5). The fragility indices for the included studies did not correlate significantly with any study characteristics.
Limitations:
Small sample, heterogeneity, and lack of inclusion of studies with continuous outcomes.
Conclusions:
The randomized trials evaluating surgical and medical interventions for diverticular disease are not robust. Changing a single-outcome event in most studies was sufficient to make a statistically significant study finding not significant. See Video Abstract .
Fragilidad De Los Resultados Estadsticamente Significativos En Ensayos Aleatorios De Enfermedad Diverticular Del Colon Una Revisin Sistemtica:
ANTECEDENTES:El valor p ha sido criticado por una determinación demasiado simplificada de si existe un efecto del tratamiento. Una alternativa es el Índice de Fragilidad. Es una representación del número mínimo de no eventos que deberían convertirse en eventos para aumentar el valor p por encima de 0,05.OBJETIVO:Determinar el IF de ensayos controlados aleatorios que evalúan la eficacia de las intervenciones para pacientes con enfermedad diverticular desde 2010 para evaluar la solidez de la evidencia actual.FUENTES DE DATOS:Se realizaron búsquedas en MEDLINE, Embase y CENTRAL desde el inicio hasta agosto de 2022.SELECCIÓN DE ESTUDIOS:Los artículos eran elegibles para su inclusión si eran ensayos aleatorizados realizados entre 2010 y 2022 con diseños paralelos de superioridad que evaluaran intervenciones en pacientes con enfermedad diverticular. Sólo se consideraron para su inclusión los ensayos aleatorizados con resultados primarios dicotómicos con un valor de p asociado menor que 0,05.INTERVENCIÓNES:Cualquier intervención quirúrgica o médica para pacientes con enfermedad diverticular.PRINCIPALES MEDIDAS DE VALORACIÓN:El índice de fragilidad se determinó sumando eventos y restando no eventos de los grupos con el menor número de eventos. Se agregaron eventos hasta que el valor p superó 0,05. El menor número de eventos requeridos se consideró índice de fragilidad.RESULTADOS:Después de examinar 1271 citas, 15 ensayos aleatorios cumplieron los criterios de inclusión. Nueve de los estudios evaluaron intervenciones quirúrgicas y seis evaluaron intervenciones médicas. El número medio de pacientes aleatorizados y perdidos durante el seguimiento por ECA fue 92 (DE 35,3) y 9 (DE 11,4), respectivamente. La mediana del índice de fragilidad fue 1 (rango: 0-5). Los índices de fragilidad de los estudios incluidos no se correlacionaron significativamente con ninguna característica del estudio.LIMITACIONES:Muestra pequeña, heterogeneidad y falta de inclusión de estudios con resultados continuos.CONCLUSIONES:Los ensayos aleatorios que evalúan las intervenciones quirúrgicas y médicas para la enfermedad diverticular no son sólidos. Cambiar un solo evento de resultado en la mayoría de los estudios fue suficiente para que un hallazgo estadísticamente significativo del estudio no fuera significativo. (Traducción- Dr. Ingrid Melo ).
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