Geriatric medicine, or geriatrics, is a sub-specialty of internal medicine that focuses on the care and well-being of older people. A geriatrician is a physician who practices geriatric medicine, specializing in the care of older people. There is no set age at which patients may be under the care of a geriatrician. Rather, this decision is determined by the individual patient's needs. ^[1]

The lecture explicitly gives the example: a 50-year-old patient suffering from Alzheimer's disease can be under the care of geriatricians. ^[1] This is an important exam point — geriatric medicine is NOT defined by a chronological age cutoff. It is defined by the patient's clinical complexity and needs.

The lecture presents a direct comparison table that is extremely high yield for understanding the conceptual distinction:

^[1]

Why this table matters from first principles: In younger patients, you typically treat a disease to restore normal physiology. In older patients, physiology is already altered at baseline, diseases present atypically (e.g., MI without chest pain, pneumonia without fever), multiple interacting conditions coexist, and the goals of care shift from cure/life prolongation toward maintaining function, quality of life, and respecting patient priorities.

1. Maintain function and independence 2. Maximize quality of life 3. Care that supports patient's goals and priorities

These three goals should be front-of-mind whenever you encounter any geriatric exam question. Every management decision in geriatrics should be filtered through: "Does this intervention help maintain function? Does it improve quality of life? Is it aligned with what this patient wants?"

• Hong Kong has the longest life expectancy in the world (85.4 years)
• Over the next 30 years, the proportion aged 65+ will rise from 18% → 40% (compared to 16% → 21% in the US)
• We are living longer, but not in healthy life years: lifespan increased by 6 years from 1990 to 2013, but DALYs increased for non-communicable diseases (Murray CJL et al., Lancet 2015)

Why this matters: The gap between lifespan and healthspan is widening. More years of life are spent in disability. This is why geriatric medicine, with its focus on function and quality of life rather than just survival, is increasingly important. The sheer demographic pressure (40% of Hong Kong's population will be ≥65) means that regardless of your specialty, you will care for older patients.

The lecture references a study: > 4800 men, age > 65, free from CV problems, median follow-up 6 years. This appears to illustrate that even in apparently healthy older adults, outcomes vary — reinforcing the concept that chronological age alone does not predict health trajectory.

One of the most notable characteristics of ageing is the failure to maintain homeostasis under conditions of physiological stress (e.g., acute illness). ^[1]

This is the single most important physiological concept in geriatric medicine. Let me explain from first principles:

Homeostatic reserve is the body's capacity to respond to stressors (infection, surgery, dehydration, temperature extremes) and return to equilibrium. In young adults, there is substantial reserve — the heart can increase output, the kidneys can concentrate urine, the immune system mounts vigorous responses. With aging, every organ system loses reserve capacity. Under resting conditions, an older person may appear functionally normal. But under stress, the system cannot compensate, leading to decompensation that manifests as geriatric syndromes (delirium, falls, incontinence, functional decline).

Age-related changes have been identified in all the body's cells, tissues, organs, and systems. ^[1]

Older adults are at increased risk of drug side effects due to decline in hepatic and renal clearance of drugs. ^[1]

• Pharmacokinetics (what the body does to the drug): ↑ body fat (↑ Vd for lipophilic drugs like diazepam → prolonged effect), ↓ lean body mass, ↓ total body water (↑ concentration of hydrophilic drugs like digoxin), ↓ albumin (↑ free fraction of protein-bound drugs like warfarin, phenytoin), ↓ renal clearance, ↓ hepatic metabolism
• Pharmacodynamics (what the drug does to the body): ↑ sensitivity to CNS depressants, anticholinergics, cardiovascular drugs

Results in young may not be extrapolated to old — many studies exclude older adults with multiple comorbidities. Benefits (effect size) of intervention may differ. Side effects profile may differ. Benefit/Risk ratio may differ. Decision/Target/Concerns of treatment may differ.

This is a critical exam concept. When you prescribe a medication or recommend an intervention for an older patient, you cannot simply apply evidence from trials conducted in younger, healthier populations. You must think about:

• Was this drug studied in patients like mine (frail, multimorbid, polypharmacy)?
• Is the benefit still likely to outweigh the risk in this individual?
• Should I adjust the target (e.g., less aggressive BP target, higher HbA1c target in frail elderly with diabetes)?

Chronological age ≠ Physiological age.

The lecture emphasizes that aging is heterogeneous. Two 80-year-olds may have vastly different physiological states — one may be running marathons, the other may be bedbound. This is why geriatric medicine uses tools like frailty assessment and CGA rather than age alone to guide management.

A geriatric syndrome primarily refers to one symptom or a complex of symptoms with high prevalence in geriatrics, resulting from multiple diseases, multiple risk factors, and interacting pathophysiological mechanisms. ^[1] They occur when the accumulated effects of impairments in multiple systems render an older person vulnerable to situational challenges. ^[1]

From first principles: A geriatric syndrome is NOT a single-organ disease. It is a clinical condition that arises from the interaction of multiple risk factors and impairments across multiple organ systems. This is fundamentally different from the traditional medical model of one disease → one diagnosis → one treatment. In geriatric syndromes, you must identify and address multiple contributing factors.

The major geriatric syndromes (often called the "Geriatric Giants" or "5 I's") include:

Mrs. Lee is an 82-year-old woman who lives alone in her own home. She has a history of hypertension, osteoarthritis, and mild cognitive impairment. Over the past six months, she has experienced recurrent falls, with the most recent fall resulting in a hip fracture.

This case illustrates the interplay of multiple geriatric syndromes:

• Multimorbidity: HTN + OA + MCI
• Falls: Recurrent — not a single event but a syndrome
• Contributing factors: OA → pain → impaired mobility; MCI → impaired judgment/attention; HTN medications → possible orthostatic hypotension; living alone → environmental hazards + no supervision
• Consequence: Hip fracture → hospitalization → risk of further functional decline, delirium, deconditioning

Two levels of ADLs:

Decline in IADLs could be an early indicator of either cognitive impairment or diminishment of physical ability. ^[1] Loss of IADLs precedes loss of BADLs. ^[1]

Why this hierarchy matters: IADLs require higher cognitive and physical function than BADLs. A patient who can still bathe and dress but can no longer manage finances or medications is showing early functional decline. By the time BADLs are lost, the person is significantly dependent. In exams, remember:

• Barthel Index → assesses BADLs (level of independence) ^[2]
• Lawton's IADL Scale → assesses IADLs
• Loss of IADLs is often the first sign of early dementia

Frailty is a clinically identifiable state of diminished physiological reserve and increased vulnerability to a broad range of adverse health outcomes. ^[1]

From first principles: Frailty represents the cumulative decline across multiple physiological systems (musculoskeletal, cardiovascular, immune, endocrine, neurological) to the point where the individual cannot maintain homeostasis under even mild stress. It is distinct from disability (which is loss of function) and comorbidity (which is having multiple diseases) — though all three often coexist.

Fit → Pre-frailty → Frailty → End-Stage Frailty

This is a spectrum, not a binary. Understanding where a patient sits on this continuum is essential for clinical decision-making.

1. Represents accelerated aging 2. Enables individualized care and targeted resource allocation 3. Guides decisions about stressful treatments

The lecture shows a key diagram illustrating the benefit-harm balance across the frailty spectrum:

^[1]

Why this is crucial: In a fit older person, aggressive treatment (surgery, chemotherapy, intensive BP control) is likely to help more than harm. As frailty worsens, the same treatment becomes increasingly likely to cause harm (prolonged deconditioning, delirium, drug side effects) without meaningful benefit. In end-stage frailty, aggressive intervention is often inappropriate and the focus should shift to comfort and quality of life.

The lecture references the efrailty.org website for choosing an appropriate tool. Key tools to know:

The 2018 past paper tested the FRAIL score as the tool for frailty assessment. ^[2]

1. Phenotypic Model (Fried): Frailty as a biological syndrome with specific physical manifestations (sarcopenia-driven cycle of weakness → slow gait → low activity → exhaustion → weight loss)
2. Deficit Accumulation Model (Rockwood): Frailty as the cumulative burden of health deficits across all domains (medical, functional, cognitive, psychosocial). More deficits = more frail.

Both models are valid and complementary. The phenotypic model is more specific for physical frailty; the deficit accumulation model captures the broader vulnerability concept.

The hazards of bed rest and hospitalization are extensively detailed in the lecture (Creditor, Ann Intern Med 1993) ^[1]:

The cascade of hospital-related harm:

USUAL AGING (↓ baseline reserves)
    ↓
Hospitalization → Bed rest → Deconditioning
    ↓
Multiple simultaneous insults:
- Tethers (IV lines, catheters, monitors) → Immobilization
- Barriers (bed rails, high beds) → Falls risk
- Sensory deprivation (no glasses, no hearing aids) → Delirium
- Isolation (unfamiliar environment, disrupted sleep) → Delirium
- Rx diet (NPO, restricted diets) → Malnutrition
- Catheter → UTI → Functional incontinence
- Physical restraints → Deconditioning, pressure sores
- Chemical restraints (antipsychotics) → Tardive dyskinesia, oversedation
    ↓
Consequences:
- ↓ Muscle strength & aerobic capacity
- ↓ Bone density (accelerated bone loss)
- ↓ pO2 (↑ closing volume when supine)
- ↓ Plasma volume → Syncope
- Pressure sores → Infection
- Delirium → Fall → Fracture
- Dehydration, malnutrition, aspiration
    ↓
NURSING HOME (loss of independence)

^[1]

Patients discharged with new ADL disability who did not recover their function by 1 month after discharge were unlikely to recover to their prior level of function. ^[1] One-year mortality is more than 2× higher than those discharged at baseline function. ^[1] (Boyd C et al., JAGS 2008)

Clinical implication: The window for functional recovery after hospitalization is narrow. Early mobilization, early rehabilitation, avoidance of unnecessary bed rest, removal of tethers, and prevention of delirium are CRITICAL during hospitalization of older adults.

Polypharmacy is increasingly common in an ageing population with multiple comorbidities. It can increase the occurrence of side effects especially in older adults due to altered pharmacokinetics, drug interactions, adverse drug reactions and non-adherence. ^[1]

From first principles: Each medication added increases the risk of:

• Drug-drug interactions (exponentially with number of drugs)
• Adverse drug reactions (older adults have altered PK/PD as discussed above)
• Prescribing cascades (side effect of drug A is treated with drug B, whose side effect is treated with drug C…)
• Non-adherence (complex regimens are hard to follow, especially with cognitive impairment)
• Falls (many drugs cause orthostatic hypotension, sedation, or dizziness)

Certain classes of drugs increase the risks of adverse effects and should be used with caution:

• NSAIDs (GI bleeding, renal impairment, fluid retention, HTN)
• Benzodiazepines (falls, oversedation, paradoxical agitation, cognitive impairment)
• Hypnotics (falls, next-day sedation)
• Diuretics (dehydration, electrolyte disturbances, orthostatic hypotension)
• Anticholinergics (delirium, constipation, urinary retention, cognitive impairment, dry mouth)
• Antidepressants (falls, hyponatremia with SSRIs, anticholinergic effects with TCAs)
• Hypoglycaemic diabetic medications (hypoglycaemia → falls, confusion, seizures)
• Anticoagulants (bleeding risk)
• Cardiac glycosides (digoxin toxicity with narrow therapeutic index)
• Antipsychotics (metabolic effects, QT prolongation, ↑ mortality in dementia)

The GC lecture on prescribing in older people (GC 079) ^[4] and STOPP/START criteria ^[5] elaborate on this extensively, providing structured tools to identify potentially inappropriate prescribing.

A multidimensional, multidisciplinary diagnostic process that aims to determine a frail elderly person's medical, psychosocial, and functional capacities and needs. ^[1]

The objective is to develop an overall tailored plan of care that addresses the concerns of the older person and/or their caregiver. Often, the appropriateness of services and place of care (e.g., long-term care vs rehabilitation) can be determined and treatment plan is reviewed periodically. ^[1]

The GC 038 lecture explicitly calls CGA the "cornerstone of geriatric medicine" and the "technology of geriatric medicine." ^[6]

Members:

• Geriatricians
• Nurses
• Dietician
• Pharmacist
• Allied health: PT (Physiotherapist), OT (Occupational Therapist), ST (Speech Therapist)
• Social Workers
• Psychologists

Why MDT? No single professional can assess and address all CGA domains. The geriatrician coordinates but relies on each team member's expertise:

• PT → mobility, strength, balance training, falls prevention
• OT → ADL assessment, home modifications, assistive devices
• ST → swallowing assessment (dysphagia screening), communication
• Dietician → nutritional assessment and supplementation
• Pharmacist → medication review, deprescribing
• Social worker → discharge planning, community resources, financial support
• Psychologist → cognitive assessment, behavioral interventions, caregiver support

CGA has been shown to:

• Reduce mortality
• Increase the likelihood of living at home at follow-up
• Improve cognitive function
• Reduce institutionalization
• Improve functional outcomes
• Be cost-effective

This evidence base is what makes CGA the cornerstone of geriatric practice.

Develop and implement models of care that integrate and provide continuity of care across primary care, hospital, and community settings. Aim to reduce hospital admissions, maintain/improve function, promote care in place.

Specific services:

• Community Geriatric Assessment Team (CGAT) — outreach to residential care homes
• Integrated Care and Discharge Support (ICDS) — transitional care to prevent readmission
• Geriatric Day Hospital (GDH) — ambulatory rehabilitation and assessment

• STOPP criteria (Screening Tool of Older Persons' Prescriptions): identifies potentially inappropriate medications that should be stopped
• START criteria (Screening Tool to Alert to Right Treatment): identifies evidence-based medications that should be started but are being omitted
• These tools operationalize the polypharmacy concepts from this lecture

• Expands on the frailty phenotype and deficit accumulation models
• Discusses interventions: exercise (especially resistance training), nutritional supplementation, medication review

• Details the evidence base for CGA
• Discusses rehabilitation principles: goal-setting, early mobilization, discharge planning

• Cognitive impairment is both a risk factor for geriatric syndromes and a condition managed within the CGA framework
• IADL decline is often the presenting feature of early dementia

• The frailty-guided benefit-harm framework directly applies to end-of-life decision-making
• In end-stage frailty, the goals shift to comfort care

• Chapter 2: CGA, Chapter 3: Acute Geriatric Care, Chapter 4: Rehabilitation, Chapter 15: Drugs, Chapter 17: Ethics, Chapter 19: End-of-life, Chapter 20: Falls, Chapter 24: Dementia and Delirium

1. MCQ/EMQ: Matching assessment scales to clinical scenarios (Barthel → BADLs, Lawton → IADLs, MoCA → cognition, FRAIL → frailty, MUST → nutrition, Berg → balance, GDS → depression)
2. SAQ: "Define CGA and list its components" or "Explain why geriatric medicine is a distinct specialty"
3. SAQ/Minicase: Case of an older patient with falls → identify contributing geriatric syndromes → outline CGA approach
4. MCQ: Drug classes to avoid/use with caution in older adults
5. SAQ: Explain the concept of hospitalization-associated disability and how to prevent it
6. MCQ: Frailty definitions, continuum, why we measure frailty

• For definitions: Use the lecture's exact wording. E.g., "Frailty is a clinically identifiable state of diminished physiological reserve and increased vulnerability to adverse health outcomes."
• For CGA: Always mention: multidimensional, multidisciplinary, individualized care plan.
• For goals of geriatric medicine: Maintain function, maximize quality of life, patient-centered goals.