The Intolerance of Uncertainty Scale- Short Form (IUS-12)

The IUS-12 (Carleton et al., 2007) is a self-report measure that assesses a person's tendency to respond to uncertainty about the future negatively. The scale contains 12 items with a 5-point Likert response scale ranging from 1 (not at all characteristic of me) to 5 (entirely characteristic of me) to gauge how people cope with uncertain situations. The IUS-12 explores two factors, Prospective IU which refers to anxiety surrounding future events (7 items) and Inhibitory IU which refers to inhibited action or experience due to uncertainty (5 items).

The internal consistency of the IUS-12 is excellent, the Cronbach's alpha of the overall scale is 0.91 and the two factors both yield alpha coefficients of 0.85 (Carleton et al., 2007). The internal consistency of the measure has been demonstrated across numerous clinical populations including those with OCD (Jacoby et al., 2013) as well as anxiety and depression (McEvoy and Mahoney, 2011). The IUS-12 has also been established as a reliable measure of IU in non-clinical populations (Fourtounas and Thomas, 2016). The construct validity of the IUS-12 has been demonstrated in several studies (Carleton et al., 2007; Jacoby et al., 2013).