Supplementary Material for: Screening second victims for emotional distress: Assessment of the clinimetric properties of the WITHSTAND-PSY Questionnaire (WS-PSY-Q)

Introduction: Adverse events (AEs) are a leading cause of patient morbidity and mortality, greatly impacting healthcare providers’ well-being (second victim (SV) phenomenon). Since it is not accurately captured by existing psychometric instruments, we developed a clinimetric instrument for assessing SVs’ emotional distress before and after an AE. Methods: Content validity and clinical utility of the WITHSTAND-PSY Questionnaire (WS-PSY-Q) were examined using cognitive interviews. Rasch analysis (n=284) was applied for clinimetric assessment (i.e., construct, concurrent, and clinical validity, internal consistency), considering two crucial psychological facets of the SV phenomenon (1st: Emotional impact of the adverse event, 2nd: Current emotional state). Results: The Rasch partial credit model was used. The 1st facet demonstrated overall acceptable clinimetric properties with the subscale anxiety meeting clinimetric threshold values (e.g., all items with ordered thresholds, Loevinger’s coefficient h≥0.40; Person Separation Reliability Index (PSI)=0.7). The 2nd facet showed overall better clinimetric properties for both subscales (e.g., h ≥0.40, PSI=0.82 and 0.79, respectively; ROC area of 0.80 and 0.86, respectively). For both datasets, item fit statistics, except those for item 19, were within the critical range (z-score