The Fragility of Significance: Why P-values and the Fragility Index Are Not Enough

The p-value has long been a cornerstone of evidence-based medicine, yet its misuse and misinterpretation are rampant. The Fragility Index (FI), developed to offer a more intuitive measure of statistical robustness, paradoxically penalizes well-designed, efficient clinical trials and remains tethered to the arbitrary p < 0.05 threshold. This commentary argues that both the p-value and the FI are insufficient as they operate within the flawed framework of Null Hypothesis Significance Testing. We propose that a shift towards a Bayesian framework is necessary. Bayesian methods, particularly the use of the Bayes Factor, align more closely with clinical reasoning by providing a direct measure of evidence for a hypothesis, allowing for a more nuanced, probabilistic approach to interpreting research findings and updating clinical beliefs.