Statistical Fragility of Outcomes on Breast Reconstruction with Acellular Dermal Matrix: A Systematic Review of Randomized Controlled Trials

Abstract

Background: Acellular dermal matrix (ADM) is pivotal in breast surgery, yet the statistical robustness of surgical outcomes remains underexplored. This study uses the fragility index (FI), reverse FI, and fragility quotient (FQ) to investigate the statistical fragility of ADM breast reconstruction outcomes.

Methods: Randomized controlled trials (2013 to present) with dichotomous outcomes were sourced from PubMed, Embase, SCOPUS, Medline, and Cochrane databases. FI and reverse FI (event reversals needed to alter outcome significance) and FQ (standardized fragility across trials) were computed and reported as median (interquartile range [IQR]). Subgroup analysis focused on intervention types.

Results: Of 33 studies screened, 19 RCTs comprising 204 outcomes were included, with a median FI of 4 (IQR, 3 to 5) and FQ of 0.039 (IQR, 0.029 to 0.070). Twenty-six outcomes achieved statistical significance, with a median FI of 3.5 (IQR, 1 to 5) and FQ of 0.033 (IQR, 0.010 to 0.073). The remaining 178 outcomes were not significant, exhibiting a median FI of 4 (IQR, 3 to 5) and FQ of 0.040 (IQR, 0.030 to 0.070). Of the 204 outcomes, 18% had a number of patients lost to follow-up equal to or surpassing the FI. By intervention type, the median FIs were similar in value but remained low.

Conclusions: ADM-related breast reconstruction outcomes are statistically fragile; thus, reversal of a few outcomes or maintaining follow-up with patients may alter the significance of findings. Future researchers are thus recommended to report FI and FQ metrics with P values to accurately portray reconstructive surgery outcomes.