Reference values for the quality of life after traumatic brain injury questionnaire and its overall scale from the adult German general population

Abstract Purpose One of the central outcomes to which attention should be paid after sustaining a traumatic brain injury (TBI) is health-related quality of life (HRQoL). The present study aims at providing reference values for the Quality of Life after Brain Injury (QoLIBRI) and its overall scale (QoLIBRI-OS) using data from the German general population. Methods A total of 3,502 individuals from the general German population completed an online survey containing adapted versions of both instruments designed for individuals without TBI. Psychometric properties, including reliability and validity analyses, were examined. Comparisons of construct assessment were conducted using 353 sex-, age-, and education-matched dyads from the general population sample and individuals after TBI. Results Both instruments demonstrated satisfactory psychometric properties in the general population sample. The construct assessment between the general population and the TBI samples was considered sufficiently comparable to derive reference values. A patient is considered to have an impaired HRQoL if their QoLIBRI or QoLIBRI-OS score falls below the 16th percentile of their reference group, which is defined by sex, chronic health condition status, age, or education. Conclusion We provided reference values in form of an open access web-based application. Clinicians can use the provided reference values to directly compare the QoLIBRI and QoLIBRI-OS scores of individuals after TBI with those of the general population. This allows them to identify impaired HRQoL domains and develop personalized treatment plans.