Psychometric Evaluation of the Snakebite Severity Score (SSS) in a Multinational Randomized Clinical Trial

Snakebite envenomation is a World Health Organization-recognized neglected tropical disease affecting 1.8 million people annually. The Snakebite Severity Score (SSS) is a composite endpoint developed to assess symptom severity across multiple body systems. The study analyzed psychometric properties of SSS using data from the BRAVO Phase 2b clinical trial involving 95 patients (45 receiving varespladib and 50 receiving placebo). The 6-item SSS version demonstrated strong reliability with a correlation coefficient of 0.8 on days 7-14 and consistent internal structure. Analysis confirmed multidimensionality with distinct contributions from local, nervous, hematological, and other symptoms. External validity was supported by moderate to strong correlations with patient and clinician-rated outcomes. SSS proved to be a reliable and valid tool for standardizing severity assessment of snakebite envenomation in clinical research.