Fragilidad en el anciano

Journal of Gerontology: MEDICAL SCIENCES 2004, Vol. 59, No. 3, 255–263

Copyright 2004 by The Gerontological Society of America

Review Article

Untangling the Concepts of Disability, Frailty, and Comorbidity: Implications for Improved Targeting and Care
Linda P. Fried,1,2,3 Luigi Ferrucci,3 Jonathan Darer,4 Jeff D. Williamson,5 and Gerard Anderson2
Departments of 1Medicine,2Epidemiology, and 3Health Policy and Management, The Johns Hopkins University School of Medicine and Bloomberg School of Public Health, Baltimore, Maryland. 4 Longitudinal Studies Section, Clinical Research Branch, National Institute on Aging, Bethesda, Maryland. 5 Mid-Atlantic Permanente Medical Group, Baltimore, Maryland. 6 Wake Forest University School of Medicine, Winston-Salem, North Carolina.

Threeterms are commonly used interchangeably to identify vulnerable older adults: comorbidity, or multiple chronic conditions, frailty, and disability. However, in geriatric medicine, there is a growing consensus that these are distinct clinical entities that are causally related. Each, individually, occurs frequently and has high import clinically. This article provides a narrative review of currentunderstanding of the definitions and distinguishing characteristics of each of these conditions, including their clinical relevance and distinct prevention and therapeutic issues, and how they are related. Review of the current state of published knowledge is supplemented by targeted analyses in selected areas where no current published data exists. Overall, the goal of this article is to provide abasis for distinguishing between these three important clinical conditions in older adults and showing how use of separate, distinct definitions of each can improve our understanding of the problems affecting older patients and lead to development of improved strategies for diagnosis, care, research, and medical education in this area.

I

N 1990, an American Medical Association white paperconcluded that ‘‘one of the most important tasks that the medical community faces today is to prepare for the problems in caring for the elderly in the 1990s and the early 21st century’’ (1). This report particularly emphasized the growing population of frail, vulnerable older adults, ‘‘the group of patients that presents the most complex and challenging problems to the physician and all health careprofessionals.’’ The vulnerable subset of the older population has also been identified as those older adults with multiple chronic conditions, or comorbidity (2,3), or those who are disabled or dependent (4). In fact, these three terms, frailty, comorbidity, and disability, are often used interchangeably to identify the physically vulnerable subset of older adults requiring enhanced care. However,recent research supports geriatricians’ perceptions that these are distinct clinical entities, although interrelated, and that clinical management of each of these has its own unique content and challenges. If this is the case, we would gain from defining how these concepts are distinct. We posit that improved clarity as to definition and criteria for distinguishing these three conditions couldimprove diagnostic accuracy and development of effective, targeted strategies for prevention and treatment. To support this goal, this article offers, first, definitions for each of the three concepts based on current knowledge and supporting evidence, so as to distinguish them, and considers the challenges at present in establishing definitive criteria. Second, we

describe the interrelationships offrailty, comorbidity, and disability. Third, we describe clinical presentations of these conditions and discuss the issues in clinical management for older adults who have each one, or two, or three of these conditions. Finally, we consider the future research questions that must be answered to further the applicability of these concepts to improving clinical practice and to facilitating clinical...