Implications for practice and research

• A better understanding of the preventability of perimortal disability is needed.

• Clinicians must regularly assess caregiver burden and be knowledgeable about resources for family caregivers.

Context

The rapidly growing number of disabled elderly is expected to tax health delivery systems, whose focus has been the management of disease rather than the prevention and management of disability. The burden of caring for the disabled rests largely with family caregivers, who commonly experience physical and emotional strain. The network of community services designed to assist caregivers is fragmented, variable and costly. The activity of daily living (ADL) disability may be especially high among individuals near the end of life.

Findings

At 24 months before death, the predicted prevalence of disability ranged from 15% for those aged 50–69 to 50% among those aged ≥90. Regardless of the starting prevalence of disability, the four age groups (50–69, 70–79, 80–89 and 90+) showed similar linear rates of increase from 24 months to around 9 months before death, after which the prevalence of disability rose sharply. At all points in time women were more disabled than men.

Commentary

Since 1982, the prevalence of one or two ADL dependencies in older adults has declined, while the prevalence of three or four ADL dependencies has risen in persons aged 75 and older.1 This paradox can be partially explained by advancements in treating disabling diseases such as arthritis, while effective pharmacotherapy and procedures like revascularisation have allowed persons with comorbidity to survive longer and experience functional decline. The burden of chronic disease predicts ADL disability.

One explanation for the high prevalence of ADL disability in the last 2 years of life is the growing prevalence of severe functional impairment among older adults. No progress has been made in reducing the length of life free of comorbidity or impaired mobility. Between 1998 and 2006, the prevalence of impaired mobility in men and women aged ≥70 increased over 50% and 21%, respectively.2 If attention was paid to reducing the functional complications of comorbidity, it is possible that the curves for disability prevalence in the last 2 years of life could be shifted downward.

Some disability represents the consequence of age-related multiorgan-system dysregulation, which may contribute to the development of ‘geriatric syndromes’ such as falls and dizziness. Among participants in the Women's Health Initiative, 3 or more of 10 assessed geriatric syndromes strongly predicted the 3-year incidence of ADL disability.3 Cumulative physiological dysregulation also has been associated with frailty,4 which in turn predicts ADL disability and mortality over 3 years.5 When disability directly stems from disease that is being optimally managed, an increase in the severity of disability over a period of months may signal the preterminal phase of the disease. If the relationship between disease and disability is unclear, then rapidly worsening ADL disability may indicate that the patient has entered a preterminal state.