The role of intervening illnesses and injuries in prolonging the disabling process.
OBJECTIVE
To evaluate the relationship between intervening illnesses and injuries leading to hospitalization and restricted activity, respectively, and prolongation of disability in four essential activities of daily living in newly disabled older persons.


METHODS
Prospective cohort study.


METHODS
Greater New Haven, Connecticut.


METHODS
Community-living persons aged 70 and older who had at least one episode of disability from March 1998 to June 2013 (N=632).


METHODS
Disability and exposure to intervening illesses and injuries leading to hospitalization and restricted activity, respectively, were assessed every month. Prolongation of disability was operationalized in two complementary ways: as a dichotomous outcome, based on the persistence of any disability, and as a count of the number of disabled activities.


RESULTS
During a median follow-up of 114 months, the 632 participants experienced 2,764 disability episodes. The mean exposure rates for hospitalization and restricted activity were 80.7 (95% confidence interval (CI)=73.7-88.4) and 173.6 (95% CI=162.5-185.5), respectively, per 1,000 person-months. After adjustment for multiple disability risk factors, the likelihood of disability prolongation was 2.5 times as great (odds ratio (OR) 2.54, 95% CI=2.05-3.15) for hospitalization and 1.2 times as great (1.21, 95% CI=1.06-1.40) for restricted activity as for no hospitalization or restricted activity, and the mean number of disabilities was 35% (risk ratio (RR)=1.35, 95% CI=1.30-1.39) greater in the setting of hospitalization and 7% (1.07, 95% CI=1.05-1.09) greater in the setting of restricted activity.


CONCLUSIONS
Intervening illnesses and injuries leading to hospitalization and restricted activity, respectively, are strongly associated with prolongation of disability in newly disabled older adults. Efforts to prevent and more-aggressively manage these intervening events have the potential to break the cycle of disability in older persons.
Department of Internal Medicine, School of Medicine, Yale University, New Haven, Connecticut.
Thomas M
TM
Gill
Heather G
HG
Allore
Evelyne A
EA
Gahbauer
Terrence E
TE
Murphy
D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D006233:Persons with Disabilities; D004194:Disease; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D011446:Prospective Studies; D013997:Time Factors; D014947:Wounds and Injuries
activities of daily living; aged; cohort studies; disability evaluation