Confirmatory factor analysis of the Dutch Intolerance of Uncertainty Scale: Comparison of the full and short version

Background and objectivesThe Intolerance of Uncertainty Scale (IUS) was developed for assessing reactions to ambiguous situations, uncertainty, and future events. The IUS has been validated in different languages, but equivocal factor structures, in combination with highly interrelated items and factors, resulted in a redundancy of the items of the English version. In the current study, the psychometric properties of the Dutch version of the IUS were examined, and compared with the shortened 12-item version (IUS-12).MethodsConfirmatory factor analyses were used to investigate different factor structures of both the full and short version of the IUS.ResultsResults indicated that the IUS-12 model with two factors (Prospective Anxiety and Inhibitory Anxiety) provides the best fit. The reduced measure has equally good internal consistency, and is highly correlated with the full version.LimitationsFuture research could investigate whether the current findings generalize to clinical populations.ConclusionTo summarize, the usage of the short 12-item version of the IUS should be encouraged in future research concerning intolerance of uncertainty.

► The short version of the Intolerance of Uncertainty Scale provides better fit than the full version.
► The IUS-12 model consists of two factors (Prospective Anxiety and Inhibitory Anxiety).
► The IUS-12 has good internal consistency, being highly correlated with the full version.
► Usage of the short IUS-12 should be encouraged in research concerning intolerance of uncertainty.