Scheubeck S, Ihorst G, Schoeller K, et al. - For treatment of multiple myeloma (MM), there are various therapeutic options available. Given an increasing interest in individualized therapeutic concepts based on patients' fitness, researchers herein compared different comorbidity scores and functional tests with respect to their influence on survival (overall survival [OS] and progression-free survival [PFS]). In addition, they developed a time-efficient, MM-specific functional assessment (FA); and examined changes in patients' FA during treatment. A prospective FA was conducted in 266 consecutive patients with MM at their initial diagnosis, which included 5 comorbidity scores and 12 commonly used geriatric functional tests. To determine changes in the course of treatment, reassessment of these 17 tests was done after ≥ 6 months. A total of 7,327 FA tests were included in the entire analysis. The univariate and multivariate Cox regression analyses suggested the greatest relevance of 4 of 17 initially evaluated scores and functional tests: the Revised Myeloma Comorbidity Index, Activity of Daily Living, the Mini-Mental State Examination, and the quality-of-life 12-Item Short Form Health Survey Physical Composite Scale. Forward and stepwise selection was applied to check the stability of the final model. On reassessing these 17 tests in 165 patients after ≥ 6 months, they identified improvement in 16 of the 17 FA tests, mostly in younger patients (<70 years old) and responding patients (partial remission or better). Outcomes overall support the utility of the newly established MM-specific FA (via the R-MCI, ADL, MMSE, and SF-12 PCS) for precise evaluation of the prognosis and risk status in MM. Its use may aid in improving treatment tolerability and should be validated to individualize MM treatment decisions in the future.