Abstract
Background: In this study, we evaluated the psychometric properties of a 10-item version of the Depression, Anxiety and Stress Scale (DASS-10) in a mild traumatic brain injury (mild TBI) sample.
Methods: Treatment-seeking adults (n = 354; mean age 36.3 years, 62% women) were recruited from outpatient rehabilitation services in New Zealand. Participants completed the DASS-10 on average 11.5 (15.0) weeks after their injury. Dimensionality, reliability, person separation index and differential item functioning of the DASS-10 were examined using Rasch analyses.
Results: Initial fit to the Rasch model for the 10-item measure was good (χ2 = 78.6, d.f. = 70, P = 0.22), with high internal consistency (Cronbach's alpha 0.89, person separation index 0.86) and acceptable unidimensionality. There was no evidence of differential item functioning for any of the person factors tested (age, gender, ethnicity, education, mental health history).
Conclusion: These findings provide preliminary support for the DASS-10 as a psychometrically sound measure of psychological distress for adults seeking treatment following mild TBI. The DASS-10 for mild TBI may be a helpful brief measure to triage mental health needs among persons referred to outpatient services after mild TBI.