Purpose: This study investigated the psychometric yield of extension of the EQ-5D-5L with a cognitive domain (EQ-5D+C) in a mixed cohort of trauma patients with repeated data. Methods: A stratified sample of patients that presented at the emergency department filled out a follow-up survey 6 and 12 months after trauma. The surveys included the EQ-5D-5L+C, EQ-VAS, and the impact of events scale-revised (IES-R), a validated post-traumatic stress disorder (PTSD) self-assessment scale. Generally, results of the EQ-5D and EQ-5D+C were compared. Psychometrics included the following: distributional features (ceiling/floor effects), discriminatory performance, convergent validity with the EQ-VAS as reference, and responsiveness to change. Psychometric properties were compared between predefined subgroups based on conditions with cognitive impact (Traumatic Brain Injury (TBI)/PTSD). Results: In total, 1799 trauma patients responded 6 and 12 months after trauma, including 107 respondents with PTSD, and 273 with TBI. Six months post-trauma, ceiling of the EQ-5D (26.3%) was reduced with 2.2% with the additional cognitive domain. Using EQ-VAS as reference, convergent validity increased slightly with the addition of the cognitive domain: correlation increasing from 0.651 to 0.664. Cognitive level was found to slightly improve over time in TBI (delta: 0.04) and PTSD patients (delta: 0.05), while (almost) no change was found in patients without TBI and PTSD. Conclusion: Adding a cognitive domain to the EQ-5D-5L slightly improved measurement properties and better captured change in health status for trauma patients with TBI and PTSD. Inclusion of the cognitive domain in the EQ-5D-5L when measuring in populations with cognitive problems should be considered.

Additional Metadata
Keywords Bolt-on, Cognition, EQ-5D-5L, HRQL, Responsiveness
Persistent URL dx.doi.org/10.1007/s11136-020-02496-4, hdl.handle.net/1765/126502
Journal Quality of Life Research
Citation
Geraerds, A.J.L.M. (A. J.L.M.), Bonsel, G.J, Polinder, S, Panneman, M.J.M, Janssen, M.F, & Haagsma, J.A. (2020). Does the EQ-5D-5L benefit from extension with a cognitive domain: Testing a multi-criteria psychometric strategy in trauma patients. Quality of Life Research. doi:10.1007/s11136-020-02496-4