Minimal clinically important difference in the World Health Organization Quality of Life Brief (WHOQOL-BREF) for adults with neurofibromatosis

Purpose This study aimed to estimate minimal clinically important difference (MCID) values for the World Health Organization Quality of Life Brief version (WHOQOL-BREF) among adults with neurofibromatosis (NF). An MCID is needed to demonstrate clinical meaningfulness of interventions for NF. Methods We estimated MCID for the WHOQOL-BREF: the quality of life (QoL) measure recommended by the Response Evaluation in Neurofibromatosis and Schwannomatosis International Collaboration. We used data from 228 clinical trial participants with NF type 1, NF type 2-related schwannomatosis, or schwannomatosis (SCHWN) who completed 10 weeks of a virtual group mind–body program targeting resiliency or a time- and attention-matched control. Following established guidelines, we estimated MCIDs using both anchor-based and distribution-based methods for physical, psychological, social relationships, and environmental domains of the WHOQOL-BREF. Results MCID results varied across method and QoL domain. Three anchor-based methods, average change (AC), change difference (CD), and regression (REG), yielded the most consistent and comparable MCID across QoL domains. Based on these methods, we recommend ranges for each QoL domain: Physical QoL (3.9–7.3), Psychological QoL (4.7–8.1), Social QoL (2.6–5.9), and Environmental QoL (4.1–6.6). Conclusion Establishing a rigorous MCID for QoL in NF is a critical step toward evaluating meaningful change in response to psychosocial interventions.