What are the evidence‑based health metrics that predict longer life and healthy aging in adults, especially those over 50?

Evidence-Based Health Metrics for Longevity and Healthy Aging

The most validated health metrics that predict longer life and healthy aging in adults over 50 are functional status (ADLs/IADLs and gait speed), comorbidity burden, body mass index, smoking status, self-rated health, and age—with functional measures being the strongest modifiable predictors. 1

Core Predictive Domains

Functional Status Measures (Strongest Predictors)

Activities of Daily Living (ADLs) and Instrumental Activities of Daily Living (IADLs) are among the most powerful predictors of mortality and functional decline in older adults. 1

• ADLs assess basic self-care: bathing, dressing, toileting, transferring, continence, and feeding 1
• IADLs evaluate higher-level functioning: managing finances, medications, shopping, meal preparation, housekeeping, transportation, and telephone use 1
• Impairment in IADLs has been directly associated with improved treatment tolerance and improved survival in older adults 1
• Limitations in functional status predict both 2-year and 4-year mortality risk 1

Gait speed is a validated objective measure strongly associated with survival in older adults. 1

• Measured via the "Timed Up and Go" (TUG) test: patient rises from chair without using arms, walks 10 feet forward, turns around, walks back, and sits down 1
• Gait speed alone predicts mortality across multiple cohort studies 1
• Scores >10 seconds or requiring arm assistance indicate higher risk of functional dependence and death 1

Comorbidity Assessment

The number and type of comorbidities are critical predictors of life expectancy and healthy aging. 1

• Common high-impact conditions include: diabetes, chronic obstructive pulmonary disease (COPD), cardiovascular disease, congestive heart failure, renal insufficiency, dementia, and depression 1
• Having 1 comorbidity increases mortality risk (OR 1.34), 2 comorbidities (OR 1.37), and 3+ comorbidities (OR 1.61) 1
• Specific comorbidities impact prognosis differently—cardiovascular disease and diabetes have particularly strong associations with mortality 1

Anthropometric Measures

Body mass index (BMI) is consistently included in validated mortality prediction indices. 1

• Underweight status (BMI <18.5) more than doubles mortality risk (OR 2.25) 1
• Both extremes of BMI predict worse outcomes, with underweight carrying higher mortality risk than obesity in older adults 1
• BMI should be interpreted alongside functional status, as sarcopenic obesity poses particular risk 1

Health Behaviors

Smoking status is one of the most consistently validated predictors across all mortality indices. 1

• Current smoking increases mortality risk (OR 1.37) even in older adults 1
• Smoking cessation benefits persist even when initiated in later life 1

Self-Reported Health

Self-rated health is a powerful subjective predictor that captures aspects not measured by objective tests. 1

• Consistently included in validated indices like the Lee Index and Schonberg Index 1
• Poor self-rated health predicts mortality independent of objective health measures 1

Cognitive Function

Cognitive impairment is a strong predictor of mortality and functional decline. 1

• Preoperative cognitive impairment increases mortality risk nearly 4-fold (OR 3.99) 1
• Can be screened with brief tools like three-item recall or clock drawing test 1
• Cognitive decline predicts loss of independence and need for institutionalization 1

Validated Assessment Tools

Comprehensive Indices

The Lee Index and Schonberg Index are the most strongly recommended validated tools for estimating life expectancy in community-dwelling older adults. 1

• Both available at ePrognosis (https://eprognosis.ucsf.edu) 1
• Lee Index validated for adults over 50 years 1
• Schonberg Index validated for adults over 65 years 1
• Both incorporate: age, sex, health conditions (diabetes, COPD), functional status (ADLs, IADLs, mobility), smoking status, BMI, and self-reported health 1
• Predict mortality with high evidence quality over 4-14 year timeframes 1

Screening Tools

The Vulnerable Elders Survey (VES-13) is a rapid screening tool that predicts death and functional decline. 1

• Score ≥3 indicates vulnerability 1
• Assesses age, self-rated health, physical function limitations, and functional disabilities 1
• Can be completed quickly by patients at home or in office 1
• Highly predictive of impaired functional status 1

Demographic Factors

Age and sex are non-modifiable but essential components of all validated mortality indices. 1

• Age 66-85 years increases mortality risk 2.67-fold compared to ≤65 years 1
• Age >85 years increases mortality risk 6.24-fold 1
• Male sex increases mortality risk (OR 1.28) compared to female sex 1

Inflammatory and Laboratory Markers

Elevated inflammatory markers predict mortality and functional decline, though not yet standard in clinical indices. 1

• High interleukin-6 and D-dimer levels associated with mortality and functional dependence in adults ≥71 years 1
• Elevated interleukin-6 and C-reactive protein associated with slower walking speed and poor grip strength in adults >70 years 1
• Preoperative C-reactive protein >10 mg/dL increases mortality risk 3.56-fold 1

Social and Environmental Factors

Institutionalization status and history of delirium are significant predictors often overlooked. 1

• Being institutionalized increases mortality risk (OR 1.54) 1
• History of delirium increases mortality risk nearly 4-fold (OR 3.9) 1
• Educational level inversely predicts mortality—college degree or more reduces risk (OR 0.45) 1

Clinical Implementation Pitfall

Chronologic age alone is unreliable for estimating life expectancy, functional reserve, or treatment complication risk. 1

• A 75-year-old woman in the healthiest quartile may live >17 years, while one in the least healthy quartile may live <7 years 1
• Functional age based on comprehensive assessment is far more predictive than chronologic age 1