Functional Impairment and Risk of Venous Thrombosis in Older Adults.

OBJECTIVES: To determine the role of age-specific risk factors for thrombosis in older age, such as functional impairment.

DESIGN: Case-control study.

SETTING: The Age and Thrombosis-Acquired and Genetic risk factors in the Elderly Study, a two-center study conducted in the Netherlands and the United States from 2008 to 2011.

PARTICIPANTS: Individuals aged 70 and older with a first-time deep venous thrombosis in the leg or pulmonary embolism (n = 401) and controls aged 70 and older (n = 431) without a history of thrombosis. Exclusion criteria were active malignancy and severe cognitive disorders.

MEASUREMENTS: The thrombotic risk associated with functional impairment, defined as impairment in two or more activities of daily living (ADLs), impaired mobility (inability to walk outside), sedentary lifestyle (≥20 h/d sleeping or sitting), and low handgrip strength (<15th percentile), was assessed. Odds ratios (ORs) adjusted for age, sex, and study center with 95% confidence intervals (95% CI) and population attributable risks (PAR) were calculated.

RESULTS: Risk of venous thrombosis was 2.9 times greater (OR = 2.9, 95% CI = 1.6-5.3) in individuals with impairment in ADLs, three times as great (OR = 3.0, 95% CI = 1.9-4.7) in those with impaired mobility, four times as great (OR = 4.0, 95% CI = 2.5-6.3) in those with a sedentary life style, and 2.3 times as great (OR = 2.3, 95% CI = 1.5-3.4) in those with weak handgrip strength. PARs were 8% for ADL disability, 13% for inability to walk outside for 15 minutes, 29% for sedentary lifestyle, and 13% for weak hand grip strength.

CONCLUSION: In individuals aged 70 and older, functional impairments are a major risk factor for venous thrombosis. These findings may help providers caring for older people be more aware of venous thrombosis risk.