Association of chronic diseases and impairments with disability in older adults: a decade of change?

BACKGROUND: Little is known about how the relationship between chronic disease, impairment, and disability has changed over time among older adults.

OBJECTIVE: To examine how the associations of chronic disease and impairment with specific disability have changed over time.

RESEARCH DESIGN: Repeated cross-sectional analysis, followed by examining the collated sample using time interaction variables, of 3 recent waves of the Health and Retirement Study.

SUBJECTS: The subjects included 10,390, 10,621 and 10,557 community-dwelling adults aged 65 years and above in 1998, 2004, and 2008.

MEASUREMENTS: : Survey-based history of chronic diseases including hypertension, heart disease, heart failure, stroke, diabetes, cancer, chronic lung disease, and arthritis; impairments, including cognition, vision, and hearing; and disability, including mobility, complex activities of daily living (ADL), and self-care ADL.

RESULTS: Over time, the relationship of chronic diseases and impairments with disability was largely unchanged; however, the association between hypertension and complex ADL disability weakened from 1998 to 2004 and 2008 [odds ratio (OR) = 1.24; 99% confidence interval (CI), 1.06-1.46; OR = 1.07; 99% CI, 0.90-1.27; OR = 1.00; 99% CI, 0.83-1.19, respectively], as it did for hypertension and self-care disability (OR = 1.32; 99% CI, 1.13-1.54; OR=0.97; 99% CI, 0.82-1.14; OR = 0.99; 99% CI, 0.83-1.17). The association between diabetes and self-care disability strengthened from 1998 to 2004 and 2008 (OR = 1.21; 99% CI, 1.01-1.46; OR = 1.37; 99% CI, 1.15-1.64; OR = 1.52; 99% CI, 1.29-1.79), as it also did for lung disease and self-care disability (OR = 1.64; 99% CI, 1.33-2.03; OR = 1.63; 99% CI, 1.32-2.01; OR = 2.11; 99% CI, 1.73-2.57).

CONCLUSIONS: Although relationships between diseases, impairments, and disability were largely unchanged, disability became less associated with hypertension and more with diabetes and lung disease.