Defining and assessing intrinsic capacity in older people: A systematic review and a proposed scoring system

Introduction: The World Health Organization has introduced the term 'intrinsic capacity' (IC) as a marker of healthy ageing. However, controversy exists on the definition and assessment of IC. We aimed to review the definitions and methods used for the assessment of IC in older adults. In addition, we proposed a new IC scoring method.Methods: A systematic search was performed in PubMed, Web of Science, Cochrane Library, Scopus and SPORTDiscus (up to February 10th, 2022) for studies assesing IC in older adults (>60 years).Results: Thirty-three studies were included. There is overall consensus on the definition of IC as well as on its different dimensions, that is: locomotion, vitality, sensory, cognition and psychological. However, the methods for assessing each of these five dimensions differ substantially across studies and there is no consensus on the best method to compute an eventual global compound score to evaluate IC taking into account all its different dimensions.Conclusions: The IC represents a highly relevant clinical concept that has been unfortunately underutilized. We propose a standardization for the assessment of each dimension of IC, with a global 0 (worst) to 10 (highest) score