Why the p Value Alone Is Not Enough: The Need for Confidence Intervals in Plastic Surgery Research

Statistical Fragility in Minimally Invasive Colorectal Surgery Studies: A Review of Randomized Trials

Purpose: The P value has been used as a statistical tool in randomized controlled trials (RCTs) to establish significance but does not provide information on the robustness of a study when used alone. The fragility index (FI) provides a supplemental approach for demonstrating robustness in RCTs that report dichotomous outcomes. This study aims to determine the statistical fragility of RCTs that compare minimally invasive techniques with open techniques in managing benign and malignant colorectal diseases. Methods: Dichotomous outcomes of minimally invasive surgery versus open surgery in RCTs from 2000 to 2023 were assessed. The overall FI and fragility quotient (FQ) of each study were calculated. Results: Of the 1377 screened studies, 50 met the inclusion criteria. In total, 820 outcomes were recorded with 747 outcomes reported as not significant (P ≥ .05) and 73 as significant (P < .05). The overall FI for all studies including all outcomes was 5 (interquartile range [IQR] 4-7) with a FQ of 0.031 (IQR 0.014-0.062). Of the 50 RCTs, 6 (12%) reported a loss to follow-up that was greater than the overall FI of 5. Conclusions: As RCTs are judged increasingly beyond just the P value, practicing colorectal surgeons will benefit from using and interpreting the FI, FQ, and the P value of studies both in analyzing future RCTs and in determining whether or not to make a change in their clinical practice if there is an efficiently true discovery.

Statistical fragility of outcomes in acellular dermal matrix literature: A systematic review of randomized controlled trials

BACKGROUND

Acellular dermal matrix (ADM) is commonly used in plastic and reconstructive surgery. With the abundance of randomized controlled trials (RCTs) reporting P-values for ADM outcomes, this study used the fragility index (FI), reverse fragility index (rFI), and fragility quotient (FQ) to evaluate the statistical stability of the outcomes in ADM RCTs.

METHODS

PubMed, Embase, SCOPUS, Medline, and Cochrane databases were reviewed for ADM RCTs (2003-present) reporting a dichotomous, categorical outcome. FI and rFI (event reversals influencing outcome significance) and FQ (standardized fragility) were calculated and reported as median. Subgroup analysis was performed based on intervention types.

RESULTS

Among the 127 studies screened, 56 RCTs with 579 outcomes were included. The median FI stood at 4 (3-5) and FQ was 0.04 (0.03-0.07). Only 101 outcomes were statistically significant with a median FI of 3 (1-6) and FQ of 0.04 (0.02-0.08). The nonsignificant outcomes had a median FI of 4 (3-5) and FQ of 0.04 (0.03-0.07). Notably, 26% of the outcomes had several patients lost to follow up equal to or surpassing the FI. Based on the intervention type, the median FIs showed minor fluctuations but remained low.

CONCLUSIONS

Outcomes from ADM-related RCTs were statistically fragile. Slight outcome reversals or maintenance of patient follow-up can alter the significance of results. Therefore, future researchers are recommended to jointly report FI, FQ, and P-values to offer a comprehensive view of the robustness in ADM literature.

Uncertainty Bounds in Clinical Trials Published in Endodontic Journals within the Last 5 Years: Are We Confident on What We Read?

INTRODUCTION

The aim of this study was to assess the prevalence of reporting of confidence intervals (CIs) in clinical trials in endodontics and discover any further associations with a range of publication characteristics.

METHODS

The electronic contents of the 3 leading endodontic journals with the highest impact factors (International Endodontic Journal, Journal of Endodontics, and Australian Endodontic Journal) were assessed from January 2016 to December 2020. The number and proportion of clinical trials reporting CIs for the difference in effectiveness/safety of competing interventions for the outcome of interest were recorded. Associations with journal, year of publication, study design, use of analyses for more complex sets of data, and others were assessed. Univariable and multivariable logistic regressions were used to identify significant predictor variables. Yearly linear trend effects were also sought.

RESULTS

A total of 141 reports of clinical trials were identified. The majority were published in the Journal of Endodontics (90/141, 63.8%) followed by the International Endodontic Journal (41/141, 29.1%). CI reporting was confirmed only for 29.1% of the sample of reports (41/141). There was strong evidence that reports of clinical trials including analyses of more complex sets of data presented 11.47 times higher odds for CI reporting (adjusted odds ratio = 11.47; 95% CI, 4.19-31.41; P < .001).

CONCLUSIONS

The inclusion of uncertainty measures as represented by the reporting of CIs is suboptimal within endodontic clinical trial reports.