Causes of Chronic Disability in the Elderly — Prevention and Management

Causes of Chronic Disability in the Elderly — Prevention and Management A. 20 High-Yield Points Definitions and Framework

Disability is an umbrella term covering impairments, activity limitations and participation restrictions (WHO ICF, 2001). Functioning is the corresponding positive umbrella term.

The ICF has two parts: - Part 1 — Functioning and Disability: Body Functions and Structures; Activities and Participation - Part 2 — Contextual Factors: Environmental Factors; Personal Factors 3. Key ICF definitions: Impairment is a problem in body function or structure · Activity is the execution of a task · Activity limitation is difficulty executing it · Participation is involvement in a life situation · Participation restriction is a problem in that involvement.

The ICF replaced the older impairment–disability–handicap model and explicitly recognises that the social and physical environment shapes functioning — disability is not a property of the person alone.

The vicious cycle: Parkinson's disease (impairment) → difficulty with self-care and mobility (activity limitation) → cannot pursue hobbies (participation restriction) → falls and fractures hip → loses confidence → becomes isolated, withdrawn and depressed. Feedback loops make functioning spiral downwards.

The major disabling events: stroke, hip fracture, other fall-related injury, and deconditioning following a major illness.

The major ongoing disabling diseases: osteoarthritis and Parkinson's disease are named explicitly; also stroke sequelae, amputation, and chronic cardiorespiratory disease.

"Almost any acute or chronic disease can reduce functioning" — but there is a specific list of common but easily overlooked causes of dysfunction in older people that must be memorised: - Impaired cognition - Impaired special senses (vision, hearing, balance) - Unstable gait and mobility - Poor health habits (alcohol, smoking, lack of exercise) - Poor nutrition - Polypharmacy - Incontinence - Psychosocial stress - Depression 9. The "geriatric giants" as classical causes — the series of I's: Immobility, Instability (falls), Incontinence, Intellectual impairment, Infection, Impairment of vision and hearing, Irritable colon, Isolation (depression), Inanition (malnutrition), Impecunity, Iatrogenesis, Insomnia, Immune deficiency, Impotence. Morley's "new geriatric giants" add frailty, sarcopenia, anorexia of ageing and cognitive impairment.

Determinants of ACTIVITY restriction — four factors: - Type of impairment (nature and severity of the disease) - Presence of associated impairments (pre-existing problems matter as much as the new one) - Degree of physiological reserve - Level of physical fitness

Determinants of PARTICIPATION restriction: - Intrinsic: attitude, personality, ability to adjust, cultural issues - Extrinsic: financial resources, housing, other resources, social supports (spouse, family, neighbours, friends, pets)

The single greatest difference from younger patients is reduced physiological reserve — recovery is prolonged and may not return to the premorbid state. But note the caution: even very old people recover from major illness, and failure to progress can seldom be blamed on reduced reserve alone. Of far greater importance is the lack of activity and physical fitness typical of older people in modern societies.

Site matters as much as size — in stroke, large lesions in some brain areas may be asymptomatic while small lesions in strategic areas cause major disability.

Disability cascades: impaired gait leads to depression and reduced social functioning; immobility of any cause — even after the cause is removed — produces secondary impairment from deconditioning and loss of musculoskeletal flexibility.

Psychological determinants: onset of impairment provokes a grief reaction — denial, anger, depression, then acceptance. Over 40% of older people become depressed after myocardial infarction, and this worsens prognosis; high rates also follow stroke despite rehabilitation. At one extreme are highly motivated patients; at the other, those who adopt the "sick role", disengage and surrender autonomy.

Kemp's motivation model — motivation is driven by four elements: the person's wants, beliefs, rewards for achievement, and the cost (pain and effort). The first three push forward; cost pulls back. The clinician intervenes by setting goals, challenging incorrect beliefs, establishing rewards and minimising cost.

Diagnostic approach: to identify the cause of new disability, look for (a) worsening of an existing chronic disease, (b) a new acute disease, or (c) one of the common occult diseases listed in point 8. Do this through a refocused history guided by the functional deficit and a focused examination.

Examination must always include — in addition to heart, lungs, extremities and neurology — postural blood pressure, vision and hearing screening, and careful observation of gait, plus MMSE. Basic labs: complete blood count and blood chemistry panel, plus targeted tests.

Rehabilitation — the UN definition: "a goal-orientated and time-limited process aimed at enabling an impaired person to reach an optimum mental, physical and/or social functional level, thus providing him or her with the tools to change his or her own life." It may compensate for lost function (technical aids) or facilitate social readjustment.

The eight steps in the rehabilitation process: 1. Assessment → 2. Setting goals → 3. Therapy → 4. Aids and adaptations → 5. Education → 6. Psychological support → 7. Evaluation → 8. Follow-up. Attached principles: - Early intervention is crucial — anticipate and avoid problems, because once established they may be irremediable (for example, shoulder subluxation in flaccid hemiplegia). - Goals must be realistic, agreed by the whole team AND the patient, with short-term (intermediate) and long-term (final) goals and flexible time frames. Patients with ambitious goals make greater progress — so set ambitious but achievable targets. - Education is a vital component — it gives the patient knowledge, skills and attitudes to minimise activity and participation restriction, and doubles as secondary prevention. - Age-associated decline is reversible: weight training increases muscle strength and improves functional capacity in older people, and lifelong trainers have muscle strength comparable to sedentary middle-aged people. - Assessment must be linked to long-term follow-up and often formal case management.

Define the disability precisely — task analysis: which step of dressing, walking or toileting fails?

Search for reversible causes — a new drug, a new illness, an intercurrent infection, a change in living conditions. When a reversible cause is found, a simple treatment may eliminate the functional impairment.

Optimise medical management — treat the disease, control pain, correct anaemia, thyroid, B12 and vitamin D; deprescribe.

Refer to the multidisciplinary team — physician, nurse, physiotherapist, occupational therapist, social worker; optimally dietician, pharmacist, speech therapist.

Set goals with the patient — short and long term, ambitious but achievable.

Therapy — exercise (resistance for strength, aerobic for endurance, balance for falls), gait re-training, ADL re-training.

Aids, appliances and home adaptation — walking aids, grab bars, raised toilet seat, shower stool, hearing aid, spectacles, footwear.

Address mood and motivation — treat depression; challenge catastrophic beliefs; use Kemp's framework.

Support the carer — carer burden is a leading cause of institutionalisation.

Discharge planning, evaluation and long-term follow-up with case management.

Global burden — the disability picture has shifted. Osteoarthritis is a leading cause of pain and disability among middle-aged and older adults; in 2020 it affected 7.6% of the global population (more than 595 million people), with cases projected to rise 60–100% by 2050, and it is expected to become the leading cause of disability worldwide by 2030. Hearing loss ranks as the third most common cause of years lived with disability globally, with its age-standardised rate still rising among those aged 60 and above. Regional analyses identify diabetes mellitus, age-related hearing loss and low back pain as the leading causes of disability in older people, distinct from the leading causes of death.

Indian data — essential for the exam. LASI wave-1 (31,464 adults aged 60 and above) found about 3% with severe ADL disability and about 6% with severe IADL disability. In the same cohort, 44.3% had no geriatric condition, 32.7% had one, 15.9% two and 7.1% had three or more; specific prevalences were underweight 26.9%, dizziness 14.5%, impaired vision 13.7%, impaired hearing 9.6%, impaired cognition 9.3%, major depressive disorder 8.2%, injurious falls 5.7% and incontinence 4.0%, with 7.4% having ADL dependency. A rural Goa study found much higher figures — ADL disability 13.7% and IADL disability 38.7% — associated with sex, education, financial dependence, comorbidities, alcoholism and sensory impairment.

Multimorbidity combinations matter more than counts. Among 197 multimorbidity combinations in LASI, the combination of hypertension, arthritis and high depressive symptoms was associated with greater ADL–IADL disability than any other combination; population attributable fractions were about 22.5% for hypertension plus depression, 21.6% for hypertension plus arthritis and 23.5% for arthritis plus depression. Adding depression to any physical multimorbidity combination sharply increases disability.

Frailty is the strongest single predictor of incident disability. A systematic review reported a pooled odds ratio of 9.82 (95% CI 4.71–20.46) for incident ADL disability in frail older adults; in LASI, frailty was strongly associated with depression (OR 2.09) and ADL difficulty (OR 1.75).

Exercise is now prescribed like a drug. The ICFSR global consensus (2025) states structured exercise prescriptions should be customised and monitored like any other medical treatment, with a multifaceted regimen of aerobic, resistance, balance and flexibility training.

Proactive, population-level disability prevention. NHS England and BGS proactive care uses the electronic frailty index to identify at-risk older people, the Clinical Frailty Scale to confirm, and a CGA covering physical, functional, social, environmental and psychological domains plus a medication review to plan care. WHO ICOPE screens six domains of intrinsic capacity with confirmed deficits triggering a personalised prevention and care plan.

CGA reduces disability outcomes. The Italian national CGA guideline (2024), from 117 studies, found CGA reduces hospitalisation, mortality, institutionalisation and delirium risk, improves prescribing appropriateness and maintains functional activities.