Abstract and Introduction
Objectives: To define frailty using simple indicators; to identify risk factors for frailty as targets for prevention; and to investigate the predictive validity of this frailty classification for death, hospitalization, hip fracture, and activity of daily living (ADL) disability.
Design: Prospective study, the Women's Health Initiative Observational Study.
Setting: Forty U.S. clinical centers.
Participants: Forty thousand six hundred fifty-seven women aged 65 to 79 at baseline.
Measurements: Components of frailty included self-reported muscle weakness/impaired walking, exhaustion, low physical activity, and unintended weight loss between baseline and 3 years of follow-up. Death, hip fractures, ADL disability, and hospitalizations were ascertained during an average of 5.9 years of follow-up.
Results: Baseline frailty was classified in 16.3% of participants, and incident frailty at 3-years was 14.8%. Older age, chronic conditions, smoking, and depressive symptom score were positively associated with incident frailty, whereas income, moderate alcohol use, living alone, and self-reported health were inversely associated. Being underweight, overweight, or obese all carried significantly higher risk of frailty than normal weight. Baseline frailty independently predicted risk of death (hazard ratio (HR)=1.71, 95% confidence interval (CI)=1.48-1.97), hip fracture (HR=1.57, 95% CI=1.11-2.20), ADL disability (odds ratio (OR)=3.15, 95% CI=2.47-4.02), and hospitalizations (OR=1.95, 95% CI=1.72-2.22) after adjustment for demographic characteristics, health behaviors, disability, and comorbid conditions.
Conclusion: These results support the robustness of the concept of frailty as a geriatric syndrome that predicts several poor outcomes in older women. Underweight, obesity, smoking, and depressive symptoms are strongly associated with the development of frailty and represent important targets for prevention.
For decades, clinicians have described older people who exhibit problems with weakness or balance as "frail," but only recently have investigators begun to define frailty clearly and operationalize it as a clinical syndrome that is causally related to, but distinct from, disability and comorbidity.[1,2] Such conceptual and operational clarification is a necessary foundation for research in this area. A cluster of indicators of frailty has been proposed that would identify study participants and patients who were at future risk of a variety of health problems. These indicators operationalized the characteristics of frailty, which included shrinking/sarcopenia, weakness, poor endurance, slowness, and low activity levels. These criteria for frailty were predictive of disability in the Cardiovascular Health Study (CHS), as measured using measures of mobility and instrumental activities of daily living. In addition, early reports have shown that those who met the criteria for frailty were more likely than those who had low or intermediate levels of the indicators to become hospitalized, fall, experience deterioration of functioning, and die over 3 to 7 years of follow-up. Replication and extension of these findings in other populations and ethnic groups is an important step in verifying the utility of this frailty construct. In addition, some of the criteria, such as grip strength, may not be readily accessible to investigators in residential settings in which older women may live the last years of their lives.
The ability to identify a set of readily measured indicators of frailty can serve as a foundation for further research about the mechanisms of frailty and interventions to modify it. In addition, identification of a set of simply measured indicators could enable clinicians to identify those at risk in community settings and assisted living environments and to target appropriate interventions to mitigate the consequences of frailty.
The purposes of this article are to:
Define frailty in the Women's Health Initiative Observational Study (WHI-OS) using indicators from widely available instruments that operationalize the characteristics of frailty identified;
Examine associations between demographic, medical history, and behavioral risk factors, including age, income, education, smoking, alcohol use, body mass index (BMI), self-assessed health, and comorbidity, and baseline and incident frailty after 3 years of follow-up; and
Determine associations between this frailty classification and future risk of death, hospitalizations, hip fractures, and activity of daily living (ADL) disability.
J Am Geriatr Soc. 2005;53(8):1321-1330. © 2005 Blackwell Publishing
Cite this: Frailty: Emergence and Consequences in Women Aged 65 and Older in the Women's Health Initiative Observational Study - Medscape - Aug 01, 2005.