Psychometric Properties of Intolerance of Uncertainty Scale (IUS‐5) in a Sample of Nurses: A Methodological Study

Background and Objective The Intolerance of Uncertainty Scale (IUS‐12) is widely used in both clinical and community studies. Due to the length and inconsistent factor structure of the IUS‐12, an abbreviated version consisting of five items (IUS‐5) has been proposed. However, no study has examined its psychometric properties aside from the preliminary work by its developers. The current study investigated the factor structure of the IUS‐5 as well as its reliability and validity. Method A sample of 315 nurses completed an online self‐report questionnaire during the COVID‐19 pandemic. Results Confirmatory factor analysis of the IUS‐5 suggested a deletion of one item. The final analysis supported a one‐factor solution on the remaining four items (IUS‐4) with a McDonald's omega of 0.77. The validity of IUS‐4 was assessed by testing its positive and negative correlations with existing related and contrary measures, respectively. Further, the validity of the IUS‐4 was supported through known‐group validation. Conclusions This is the first psychometric assessment of the IUS‐5 measure of intolerance of uncertainty in a sample of nurses. Results from the current study supported a shorter measure of four items. However, more work needs to be conducted to examine the IUS‐4 and IUS‐5 in samples of healthcare providers with different cultural and linguistic backgrounds.