THE DISABLING PROCESS

Older adults 60 times more likely to develop a disability after hospitalization.

The disabling process in people older than 70 usually begins within a month of an illness or injury that results in a period of inactivity lasting as little as half a day, and when it's associated with hospitalization, the risk of developing a disability is vastly greater, according to the results of the Precipitating Events Project, a prospective cohort study.

Seven hundred fifty-four nondisabled older adults were followed for five years. At the beginning of the study, research nurses performed comprehensive health assessments in the home, including assessments for hypertension; myocardial infarction; congestive heart failure; stroke; diabetes mellitus; arthritis; hip fracture; fracture of a wrist, an arm, or the spine since age 50; leg amputation; chronic lung disease; cirrhosis or other liver disease; cancer; and Parkinson disease. Cognitive status was measured with the Mini-Mental Status Examination, depressive symptoms according to the Center for Epidemiologic Studies Depression scale, and physical frailty with the rapid gait test, assessments that were made again 18 and 36 months later. To be eligible for the study, participants had to be independent in bathing, dressing, transferring from a chair, and walking inside the house.

Every month, research staff members telephoned participants and asked whether they had been either confined to bed for half a day or longer or hospitalized during the preceding month as a result of either injury or illness (the "intervening event"), and either circumstance was considered to be an episode of "restricted activity." Research staff also asked participants whether they had needed assistance in bathing, dressing, transferring from a chair, or walking inside the house. A new disability was identified when a participant needed assistance with one of more of those activities of daily living during the preceding month but not during the month immediately preceding that one. Researchers also collected data on persistent disability, defined as a new disability lasting at least two months, and admission to a nursing home because of disability.

Restricted activity was significantly associated with the development of a new disability, the incidence rates of which (per 100 person-months) were as follows: participants who had been hospitalized, 31.9%; participants who had experienced at least half a day of restricted activity, 3.4%; and participants who had experienced no intervening event, 0.61%. The hazard ratio for hospitalization was 59.8, and for restricted activity only, 5.11. The hazard ratio for nursing home admission within a month of hospitalization was an astonishing 223. Hospitalization was associated with 50% to 80% of new disabilities, and restricted activity at home attributable to illness or injury was associated with 5% to 19% of them. Restricted activity itself, rather than any specific medical diagnosis, was found to be associated with the disabling process. Formerly, the study authors had observed that older adults usually find that they restrict their activities because of a combination of medical problems rather than a single specific diagnosis.

The factors that study participants most often cited in the restriction of their activities were fatigue, pain or stiffness in the joints or back, and dizziness or unsteadiness. Those symptoms are associated with falling-and falls that resulted in injuries necessitating hospitalization carried the greatest risk of the development of a disability. In addition to the direct effects of illness and injury, hospitalization or restricted activity or both may themselves serve as detriments to independent functioning. Because the study included monthly follow-up for an average of more than three years, it suggests that there is a causal connection between restricted activity in general, and hospitalization in particular, and the development of a disability. To understand how the process unfolds after hospitalization and periods of restricted activity, further research is necessary.

Measures to prevent falling at home and outside it, better restorative treatment after hospitalization, and improvements in the treatment of pain and stiffness could result in fewer disabilities and nursing home admissions, improving the quality of life among older adults.

Gill TM, et al. JAMA 2004;292(17):2115-24.