Functional Impairment and Risk of Venous Thrombosis in Older Adults

ObjectivesTo determine the role of age-specific risk factors for thrombosis in older age, such as functional impairment. DesignCase-control study. SettingThe Age and ThrombosisAcquired and Genetic risk factors in the Elderly Study, a two-center study conducted in the Netherlands and the United States from 2008 to 2011. ParticipantsIndividuals 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. MeasurementsThe 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. ResultsRisk 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. ConclusionIn 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.