The QOLIBRI development was undertaken to create a sensitive instrument that can pick up important differences in TBI specific HRQoL. Sensitivity has been shown in two international samples.

Each of QOLIBRI scales is internally consistent (Cronbach’s alpha ranges from 0.75 to 0.89), and shows good test-retest reliability (intraclass correlations ranged from 0.78 to 0.85).

The analysis also indicates that there is a common overall health-related quality of life factor, and this is captured by a total QOLIBRI score. The QOLIBRI Total has good internal consistency (alpha=.95) and good test-retest reliability (ICC=.91). Although the QOLIBRI Total score is useful as an overall summary, the analysis indicates that it does not completely describe variation in HRQoL, and that this is more fully and consistently measured by the profile of individual scales. In factor analysis a single-factor solution accounted for only 37% of the variance, while six factors accounted for 59%.

Structural Equation Modelling indicates a satisfactory fit with a model consisting of six latent variables on one level (i.e. corresponding to the scales). Recent studies conducted in multilingual TBI samples as well as in general samples provide further evidence in favour of the six-factor model (Gorbunova et al., 2020, Steinbuechel et al., 2021, Krenz et al., 2023). For this reason, the concept of a second-order factor (i.e., with an overlying HRQoL factor) will not be pursued further.

Further details concerning psychometrics in the international sample can be found in:

Gorbunova, A., Zeldovich, M., Voormolen, D. C., Krenz, U., Polinder, S., Haagsma, J. A., Hagmayer, Y., Covic, A., Real, R. G. L., Asendorf, T., & von Steinbüchel, N. V. (2020). Reference Values of the QOLIBRI from General Population Samples in the United Kingdom and The Netherlands. Journal of clinical medicine, 9(7), 2100. https://doi.org/10.3390/jcm9072100

Krenz, U., Greving, S., Zeldovich, M., Haagsma, J., Polinder, S., von Steinbüchel, N., & On Behalf Of The Center-Tbi Participants And Investigators (2023). Reference Values of the Quality of Life after Brain Injury (QOLIBRI) from a General Population Sample in Italy. Journal of clinical medicine, 12(2), 491. https://doi.org/10.3390/jcm12020491

von Steinbüchel, N., Wilson, L., Gibbons, H., Hawthorne, G., Höfer, S., Schmidt, S., Bullinger, M., Maas, A., Neugebauer, E., Powell, J., von Wild, K., Zitnay, G., Bakx, W., Christensen, A. L., Koskinen, S., Sarajuuri, J., Formisano, R., Sasse, N., Truelle, J. L., & QOLIBRI Task Force (2010). Quality of Life after Brain Injury (QOLIBRI): scale development and metric properties. Journal of neurotrauma, 27(7), 1167–1185. https://doi.org/10.1089/neu.2009.1076

von Steinbüchel, N., Wilson, L., Gibbons, H., Hawthorne, G., Höfer, S., Schmidt, S., Bullinger, M., Maas, A., Neugebauer, E., Powell, J., von Wild, K., Zitnay, G., Bakx, W., Christensen, A. L., Koskinen, S., Formisano, R., Saarajuri, J., Sasse, N., Truelle, J. L., & QOLIBRI Task Force (2010). Quality of Life after Brain Injury (QOLIBRI): scale validity and correlates of quality of life. Journal of neurotrauma, 27(7), 1157–1165. https://doi.org/10.1089/neu.2009.1077

Steinbuechel, N. V., Rauen, K., Bockhop, F., Covic, A., Krenz, U., Plass, A. M., Cunitz, K., Polinder, S., Wilson, L., Steyerberg, E. W., Maas, A. I. R., Menon, D., Wu, Y. J., Zeldovich, M., & The Center-Tbi Participants And Investigators (2021). Psychometric Characteristics of the Patient-Reported Outcome Measures Applied in the CENTER-TBI Study. Journal of clinical medicine, 10(11), 2396. https://doi.org/10.3390/jcm10112396