Year, Volume, Issue, Page(s):14, 35, 3, 485-492
Study examined the factor structure of the Pittsburgh Sleep Quality Index (PSQI) in a sample of individuals with traumatic brain injury (TBI) and tested the one-, two-, and three-factor models derived from previous studies in other populations. The PSQI is a measure of sleep quality in which respondents are asked to answer questions about their sleep over the past month. PSQI data was collected during telephone interviews conducted with 243 subjects who had sustained a TBI. Participants were a subset of individuals with TBI enrolled in the National Institute of Disability and Rehabilitation Research (NIDRR) TBI Model Systems program, a prospective, longitudinal multi-center study that collects data about individuals with TBI, their injury, and their outcomes. All participants were approximately one year post-injury. Factor analyses were conducted (exploratory and confirmatory) to examine the factor structure of the PSQI. Consistent with previous research, this study found that the single-factor model is not the optimal factor structure for the PSQI in people with TBI. Results confirm the fit of models previously tested but also reveal an alternative conceptualization of sleep containing both qualitative and quantitative factors. While the 3-factor model best fits the data in this TBI sample, the use of a 2-factor model is acceptable and may be more clinically relevant due to the grouping of time-related variables that could provide important information with regard to circadian rhythm disorders.