The Factor Structure of the Pittsburgh Sleep Quality Index in Persons with Traumatic Brain Injury. A NIDRR TBI Model Systems Module Study

Background: Sleep disturbances are common following traumatic brain injury (TBI). The Pittsburgh Sleep Quality Index (PSQI) is a widely used measure of sleep quality that has been used in numerous populations. Although this measure has been used in TBI research, there are few studies examining the psychometric properties in this population.

Objective: The current study examined the factor structure of the PSQI in a sample of persons with TBI and tested the one, two, and three factor models derived from previous studies in other populations.

Methods: A telephone interview was conducted with 243 individuals who had sustained a TBI. All participants were approximately one year post-injury. Factor analyses were conducted (exploratory and confirmatory) to examine the factor structure of the PSQI.

Results: Results confirm the fit of models previously tested in the literature but also reveal an alternative conceptualization of sleep containing both qualitative and quantitative factors.

Conclusions: 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.