Comprehensive Geriatric Assessment: Research Evidence for Geriatric Syndromes and Medical/Surgical Diagnoses
Comprehensive Geriatric Assessment (CGA) reduces disability, hospitalization, and institutionalization while improving quality of life in older adults, with the strongest evidence supporting its use in acute hospital settings, particularly in geriatric medicine, oncology, and orthopedic/trauma surgery wards 1.
Core Definition and Components
CGA is an interprofessional diagnostic process that identifies medical, psychosocial, cognitive, physical, and functional needs of older adults to develop a coordinated care plan 1. The most widely accepted definition describes it as "a multidimensional, multidisciplinary process which identifies medical, social and functional needs, and the development of an integrated/co-ordinated care plan to meet those needs" 2.
Minimum requirements for valid CGA include at least 15 minutes duration and assessment of six core dimensions: self-help ability, mobility, cognitive function/delirium, affect, nutrition, and social situation 3.
Evidence for Hospital-Based CGA
Acute Care Settings
High-certainty evidence demonstrates that CGA for hospitalized older adults increases the likelihood patients will be alive and in their own homes at 3-12 months follow-up (RR 1.06,95% CI 1.01-1.10; 16 trials, 6799 participants) 4. This translates to approximately 3-4 additional patients per 100 treated who remain alive and independent at home 5.
The evidence shows:
- No difference in mortality alone (RR 1.00,95% CI 0.93-1.07; high-certainty evidence) 4
- Significant reduction in nursing home admissions (RR 0.80,95% CI 0.72-0.89; high-certainty evidence) 4
- Little or no difference in dependence (RR 0.97,95% CI 0.89-1.04) 4
Ward-Based vs. Team-Based Models
Ward-based CGA units demonstrate superior outcomes compared to mobile consultation teams. Ward-based management produces 4 additional patients per 100 living at home (95% CI 1-7), while team-based consultation shows no benefit (0 per 100,95% CI -4 to +5) 5. This distinction is critical for implementation planning.
Strongest Evidence by Specialty
The 2023 British Journal of Anaesthesia systematic review identified strongest evidence for CGA effectiveness in:
- Acute geriatric medicine wards
- Oncology departments
- Orthopedics/trauma surgery units
Weaker but supportive evidence exists for:
- Emergency departments
- General surgery wards 6
Evidence for Geriatric Syndromes
Frailty Management
CGA is the evidence-based cornerstone for managing frailty, using multidimensional assessment of comorbid, cognitive, and functional limitations 6. The 2026 systematic review confirms that CGA significantly reduces mortality risk, preserves independence in activities of daily living, reduces hospital length of stay, and delays frailty progression 7.
Four themes supported by strong evidence for perioperative frailty care:
- Performing preoperative frailty assessments using validated multidimensional instruments
- Reducing urinary catheter use
- Following multidisciplinary care throughout perioperative period
- Early involvement of multidisciplinary teams with daily communication 6
Delirium Prevention
Frailty increases delirium risk more than four-fold, and moderate-certainty evidence supports multi-component interventions to reduce delirium risk in hospitalized patients 6. While CGA guidelines recommend preoperative delirium risk assessment by multidisciplinary teams, this specific recommendation lacks strong direct evidence in frailty populations 6.
Falls and Mobility
The Geriatric 5Ms framework, which structures modern CGA implementation, prioritizes mobility and fall risk assessment as the second critical domain after cognitive evaluation 1. However, only two studies reported falls as serious adverse events, showing no significant impact (RR 0.82,95% CI 0.58-1.17; very low-certainty evidence) 8.
Multimorbidity
More than two-thirds of people with frailty have multimorbidity, and CGA effectively guides assessment and treatment of co-existing conditions 6. The 2026 evidence confirms a bidirectional relationship between frailty and multimorbidity, mediated by chronic inflammation, immunosenescence, hormonal dysregulation, and sarcopenia 7.
Evidence for Surgical Populations
Preoperative Assessment
Strong evidence supports preoperative frailty screening for all patients ≥65 years using validated multidimensional scales (6 recommendations across 5 guidelines; 10 recommendations across 8 guidelines respectively) 6. A positive frailty screen should trigger CGA, though this recommendation appears in only 3 guidelines without strong supporting evidence 6.
Perioperative Care
Multidisciplinary teams should be involved early in assessment and maintain daily communication throughout the perioperative period (8 recommendations across 4 guidelines; strong evidence) 6. Additional perioperative recommendations with weaker evidence include:
- Enhanced Recovery program adherence
- Individualized analgesia limiting opioids and NSAIDs
- Appropriate aids for physical, sensory, or cognitive impairments 6
Oncology
The G8 questionnaire is specifically recommended for screening oncology patients who would benefit from CGA 6. This represents one of the few setting-specific screening tools with guideline support.
Community-Based CGA Evidence
Low-certainty evidence suggests community-based CGA may reduce unplanned hospital admissions (RR 0.83,95% CI 0.70-0.99; 6 studies, 1716 participants) for community-dwelling frail older adults 8. However:
- No difference in mortality (RR 0.88,95% CI 0.76-1.02; moderate-certainty evidence)
- No difference in nursing home admissions (RR 0.93,95% CI 0.76-1.14; high-certainty evidence)
- Uncertain effect on emergency department visits (very low-certainty evidence) 8
Outpatient Settings
Low-quality evidence from 2025 shows CGA in hospital outpatient clinics does not significantly affect mortality, hospitalization, functional status, or cost 9. Very low-quality evidence suggested favorable quality of life at 3 and 12 months 9. The high variability in CGA implementation across centers limits robust conclusions.
Cost-Effectiveness Evidence
CGA increases healthcare costs by an average of £234 per participant (95% CI £-144 to £605; low-certainty evidence) 4. Cost-effectiveness analysis shows:
- £19,802 per QALY gained (0.012 QALY increase; low-certainty evidence)
- £6,305 per life year gained (0.037 LY increase; low-certainty evidence)
- £12,568 per life year living at home gained (0.019 LYLAH increase; low-certainty evidence)
The probability that CGA is cost-effective at a £20,000 ceiling ratio is 50% for QALYs, 89% for life years, and 47% for life years living at home 4.
Implementation Framework: The Geriatric 5Ms
The 2024 Mayo Clinic guideline provides a practical structure for CGA implementation 1:
- Mind: Cognitive and psychological assessment (influences all other domains)
- Mobility: Fall risk and functional mobility evaluation
- Medications: Reconciliation focusing on high-risk medications
- What Matters Most: Patient's meaningful health goals and care preferences
- Multicomplexity: Intersection of multiple chronic conditions and social determinants
This framework addresses the critical gap where disease-focused care delays identification of geriatric syndromes that negatively affect functional status, quality of life, and mortality 1.
Critical Implementation Considerations
CGA effectiveness depends heavily on delivery model. Ward-based units with dedicated geriatric expertise consistently outperform mobile consultation teams 5. The 2025 and 2026 evidence emphasizes that CGA should be initiated as early as possible in the acute care pathway, ideally in emergency departments and acute medical units 10.
Common pitfall: Many guidelines lack implementation guidance on barriers, facilitators, resource implications, and monitoring criteria, limiting real-world application 6. Standardized CGA implementation supported by validated digital frailty indices and multidisciplinary teams is recommended 7.
Major limitation: Surgical patients with frailty have been largely excluded from clinical trials, requiring clinicians to integrate indirect evidence, opinion, and experience in decision-making 6.