Beyond P-Values: How the Relative Risk Index Enhances Statistical Reliability in Orthopaedic Research

 Orthopaedic researchers increasingly recognize the limitations of traditional statistical measures. In a recent letter to the Journal of the American Academy of Orthopaedic Surgeons, Dr. Thomas Heston introduces the Relative Risk Index (RRI) as a valuable complement to the established Fragility Index (FI). The core difference lies in their focus: while FI measures susceptibility to P-value changes based on minimal outcome alterations, RRI evaluates the magnitude of change needed to reach therapeutic equivalence across all data. This distinction proves significant in tranexamic acid research, where FI suggests fragility but RRI indicates robustness. The RRI's value stems from its independence from arbitrary P-value thresholds and its alignment with clinical decision-making processes. As orthopaedic surgery continues advancing evidence-based practice, adopting complementary statistical approaches like RRI could enhance research reliability and ultimately improve surgical outcomes through more nuanced evaluation of intervention efficacy.
Citation: Heston TF. Letter to the Editor: The Relative Risk Index: A Complementary Metric for Assessing Statistical Fragility in Orthopaedic Surgery Research. J Am Acad Orthop Surg. 2025 Apr 1;33(7)
doi: 10.5435/JAAOS-D-24-00473