Although the authors1 used multivariate model, it is still unclear how to integrate multimorbidity and its interactions – additive, synergistic, or otherwise – with the concept of frailty. Multimorbidity is defined as the co-occurrence of ≥2 chronic conditions such as diabetes, hypertension, depression, anxiety, cancer, etc.13 In this population, multimorbidity is the norm, occurring in approximately 85 % of individuals.13 Frailty is a syndrome defined as an increase vulnerability in older