In this study, we evaluated the factor structure, reliability estimates, item parameters, and differential correlates of the short form of the Intolerance of Uncertainty Scale (Carleton, Norton, & Asmundson, 2007) in samples of undergraduate women (n = 387) and men (n = 276) ranging in age from 18 to 49 years (M = 20.20, SD = 3.91). This instrument was designed to measure 2 facets of intolerance of uncertainty— prospective anxiety and inhibitory anxiety—although total scores on the measure are often used. A major objective of this study was to determine the degree to which derivation of total versus subscale scores is empirically permissible. Comparison of a bifactor model to a unidimensional model and a 2-factor correlated traits model indicated that the bifactor model exhibited superior fit to the sample data. This model provided evidence of a strong general intolerance of uncertainty factor that was more reliable and accounted for significantly more common variance than either subscale factor. Examination of the item response theory slope parameters revealed negligible bias in the measure’s items across genders. Finally, a series of simultaneous regression analyses was conducted to examine differential correlates of the measure’s total scale scores for men and women.

Insomnia occurs in about one of five service members prior to a military deployment and is associated with a wide array of psychosocial stressors and mental and physical health problems.

Registry: ClinicalTrials.gov; Title: Comparing Internet and In-Person Brief Cognitive Behavioral Therapy of Insomnia; Identifier: NCT01549899; URL: https://clinicaltrials.gov/ct2/show/NCT01549899.

Study Objectives To examine sleep disorder symptom reports at baseline and posttreatment in a sample of active duty U.S. Army Soldiers receiving treatment for posttraumatic stress disorder (PTSD). Explore sleep-related predictors of outcomes. Methods Sleep was evaluated in 128 participants in a parent randomized clinical trial comparing Spaced formats of Prolonged Exposure (PE) or Present Centered Therapy and a Massed format of PE. In the current study, Spaced formats were combined and evaluated separately from Massed. Results At baseline, the average sleep duration was < 5 h per night on weekdays/workdays and < 6 h per night on weekends/off days. The majority of participants reported clinically significant insomnia, clinically significant nightmares, and probable sleep apnea and approximately half reported excessive daytime sleepiness at baseline. Insomnia and nightmares improved significantly from baseline to posttreatment in all groups, but many patients reported clinically significant insomnia (>70%) and nightmares (>38%) posttreatment. Excessive daytime sleepiness significantly improved only in the Massed group, but 40% continued to report clinically significant levels at posttreatment. Short sleep (Spaced only), clinically significant insomnia and nightmares, excessive daytime sleepiness, and probable sleep apnea (Massed only) at baseline predicted higher PTSD symptoms across treatment course. Short weekends/off days sleep predicted lower PTSD symptom improvement in the Spaced treatments. Conclusions Various sleep disorder symptoms were high at baseline, were largely unchanged with PTSD treatment, and were related to worse PTSD treatment outcomes. Studies are needed with objective sleep assessments and targeted sleep disorders treatments in PTSD patients. Clinical Trial Registration NCT01049516.