Which validated vital‑sign, laboratory, and functional assessments predict longevity in adults aged 45 years and older?

Validated Predictors of Longevity in Adults Aged 45 and Above

The strongest evidence-based predictors of longevity are functional status measures (particularly gait speed, ADL/IADL independence), comorbidity burden, and self-rated health, which consistently outperform chronologic age alone in predicting mortality across multiple validated prognostic indices. 1

Functional Status Assessments (Highest Predictive Value)

Objective Physical Performance Measures

• Gait speed is the single most powerful objective predictor of survival in adults over 45, with slower walking speed directly correlating with increased mortality risk across international cohort studies 1, 2
• The Timed Up-and-Go (TUG) test measuring time to rise from a chair, walk 10 feet, and return predicts mortality; scores >10-12 seconds indicate elevated risk 3, 1
• Grip strength discriminates well between survivors and decedents in population studies 2
• Chair stand performance (ability to rise from seated position without arm assistance) is incorporated into validated mortality prediction tools 3, 1

Activities of Daily Living

• Impairment in instrumental activities of daily living (IADLs) is among the most powerful predictors of both mortality and functional decline, consistently ranking in the top tier across all validated indices 3, 1
• Basic ADL limitations (bathing, dressing, eating, toileting, transferring) predict 2-year and 4-year mortality independent of other factors 3, 1
• IADL deficits (managing medications, finances, shopping, transportation) are directly associated with reduced survival even in those with good performance status 3, 1

Validated Screening Tools

• The Vulnerable Elders Survey-13 (VES-13) predicts death and functional decline; scores ≥3 identify vulnerable individuals at elevated mortality risk 3
• The Short Physical Performance Battery (SPPB) with scores <9 is associated with increased mortality, nursing home placement, and functional decline 3

Comorbidity Burden

Number and Type of Conditions

• Mortality risk increases progressively with comorbidity count: 1 condition (OR 1.34), 2 conditions (OR 1.37), ≥3 conditions (OR 1.61) 1
• Specific high-impact comorbidities include diabetes mellitus, chronic obstructive pulmonary disease, congestive heart failure, chronic kidney disease, peripheral arterial disease, and atrial fibrillation 3, 1
• Cardiovascular disease and diabetes confer especially strong mortality risk independent of other factors 3, 1

Validated Comorbidity Indices

• The Charlson Comorbidity Index (CCI), Cumulative Illness Rating Scale (CIRS), and Adult Comorbidity Evaluation-27 (ACE-27) stratify mortality risk based on number and severity of conditions 3
• These indices should be used in conjunction with functional assessments for optimal prediction 3

Laboratory and Inflammatory Markers

Emerging Biomarkers

• Elevated interleukin-6 and D-dimer levels are associated with mortality and functional dependence in adults ≥71 years 3, 1
• High C-reactive protein (>10 mg/dL) increases mortality risk 3.56-fold 1
• Elevated interleukin-6 and CRP correlate with slower walking speed and reduced grip strength in adults >70 years 3, 1
• Serum cystatin-C (marker of renal function) is incorporated into validated physiologic indices predicting mortality 4, 5

Traditional Laboratory Values

• Blood urea nitrogen (BUN) >26 mg/dL is included in validated mortality risk scores 3
• Serum creatinine ≥1.8-2.0 mg/dL predicts 1-year mortality 3
• Fasting glucose levels contribute to physiologic indices of aging 4, 5
• Serum albumin discriminates between survivors and decedents 2

Anthropometric and Vital Sign Measures

Body Mass Index

• Underweight status (BMI <18.5) more than doubles mortality risk (OR 2.25), carrying higher risk than obesity in older adults 1
• Both BMI extremes predict poorer outcomes, but interpretation must be combined with functional status due to sarcopenic obesity 1
• BMI is a core component of the Lee and Schonberg validated mortality indices 1

Physiologic Measurements

• Systolic blood pressure across the full range of values contributes to physiologic indices predicting mortality 4, 5
• Forced vital capacity (pulmonary function) is incorporated into validated mortality prediction models 4, 5
• Serial vital sign assessments have increased sensitivity compared to single measurements, especially when viewed against individualized reference ranges 6

Cognitive Function

• Pre-operative cognitive impairment raises mortality risk nearly four-fold (OR 3.99) 1
• Digit Symbol Substitution Test scores predict mortality and are included in physiologic indices 4, 5
• Brief cognitive screening (three-item recall, clock-drawing) effectively identifies deficits associated with mortality 1
• Cognitive decline is associated with elevated D-dimer levels 3

Self-Rated Health and Behavioral Factors

Subjective Health Assessment

• Self-rated health independently predicts mortality beyond objective clinical measures and is incorporated into the Lee and Schonberg indices 1
• Poor self-rated health is among the top predictors across international cohort studies 2

Health Behaviors

• Current smoking elevates mortality risk (OR 1.37) in adults over 45 1
• Exercise frequency discriminates well between survivors and decedents 2
• Smoking cessation confers survival benefit even when initiated later in life 1

Comprehensive Validated Prognostic Indices

Recommended Tools for Adults ≥45 Years

• The Lee Index (validated for adults ≥50 years) and Schonberg Index (validated for adults ≥65 years) are the most strongly recommended tools for estimating life expectancy in community-dwelling adults 1
• Both indices incorporate age, sex, diabetes, COPD, functional status (ADLs, IADLs, mobility), smoking status, BMI, and self-rated health 1
• These predict mortality with high-quality evidence over 4- to 14-year horizons 1

Physiologic Indices

• The Modified Physiologic Index combining systolic blood pressure, forced vital capacity, cognitive testing, cystatin-C, and fasting glucose predicts mortality 19% better per index unit and attenuates the age association with mortality by 33% 4
• A physiologic index of comorbidity using carotid ultrasound, pulmonary function, brain MRI, cystatin-C, and fasting glucose shows those with highest scores (7-10) have 3.80-fold greater mortality than those with lowest scores (0-2) 5

Demographic Factors

• Chronologic age alone is unreliable for estimating life expectancy; functional age derived from comprehensive assessment is far more predictive 3, 1
• Compared with ≤65 years, ages 66-85 increase mortality risk 2.67-fold; age >85 raises risk 6.24-fold 1
• Male sex is associated with higher mortality (OR 1.28) versus female sex 1
• A 75-year-old woman in the healthiest quartile may live >17 years, whereas one in the least healthy quartile may live <7 years, illustrating the superiority of functional over chronologic age 1

Social and Environmental Predictors

• Institutionalization raises mortality risk (OR 1.54) 1
• Prior delirium episode increases mortality nearly four-fold (OR 3.9) 1
• Higher educational attainment (college degree or more) reduces mortality risk (OR 0.45) 1
• Social support and home environment assessments contribute to comprehensive geriatric assessment 3

Clinical Implementation Algorithm

For adults aged 45-64 years:

• Apply the Lee Index incorporating functional status, comorbidities, smoking, BMI, and self-rated health 1
• Measure gait speed as the single most powerful objective predictor 1, 2
• Assess IADL independence as the strongest functional predictor 1, 2

For adults aged 65 and above:

• Use the Schonberg Index for comprehensive mortality prediction 1
• Screen with VES-13 (score ≥3 indicates vulnerability requiring full assessment) 3
• Perform TUG test (>10-12 seconds indicates elevated risk) 3, 1
• Measure comorbidity burden using validated indices (CCI, CIRS, or ACE-27) 3

Common pitfalls to avoid:

• Do not rely on chronologic age alone, as functional age is far more predictive 3, 1
• Do not use single-point vital sign measurements; serial assessments against individualized reference ranges have greater sensitivity 6
• Do not assess BMI without considering functional status, as sarcopenic obesity markedly increases risk 1
• Do not overlook self-rated health, which independently predicts mortality beyond objective measures 1, 2