Pediatric Frailty: From concept to action – Advancing measurement, biomarkers, and clinical integration

Frailty in pediatric populations is an emerging but increasingly relevant construct that extends beyond physical vulnerability to encompass psychological, social, and developmental dimensions. Although initially conceptualized within gerontology, frailty has gained traction in pediatric healthcare, particularly as it pertains to children living with chronic illnesses, disabilities, or complex care needs. Yet, despite its growing clinical and scientific relevance, pediatric frailty remains an underdeveloped field, with ongoing challenges in its definition, measurement, and integration into practice. This letter outlines the historical evolution of pediatric frailty, identifying four key developmental phases: pre-reflective, reflective, definitional, and research. Initially used synonymously with vulnerability, frailty gradually evolved into an analytical framework supported by statistical modeling, and later became a clinically relevant concept tied to familial and psychological dimensions. The definitional phase saw frailty recognized in pediatric subspecialties, especially oncology and cardiology, with attention to inherited patterns and intergenerational health risks. In the current research phase, efforts have intensified to operationalize frailty through validated scores, biomarkers, and predictive indices tailored to pediatric populations. Notably, frailty is increasingly recognized as a dynamic and multidimensional syndrome that necessitates a broader perspective encompassing family systems and social determinants of health. Despite these advancements, significant gaps persist in the conceptual and methodological foundations of pediatric and familial frailty. There remains a pressing need to develop age-appropriate tools, validate longitudinal trajectories, and incorporate frailty screening into pediatric care pathways. Bridging the gap between conceptual insights and clinical implementation is crucial for enhancing outcomes for vulnerable children and their families. We call on the pediatric clinical communities to prioritize frailty as a core component of child health research and policy. Integrating psychosocial and developmental indicators alongside biological markers will enable early identification and targeted interventions. The evolution of frailty from a theoretical construct to a measurable, actionable clinical entity is within reach—provided future research continues to advance with precision, interdisciplinary collaboration, and patient-centered focus.