Individuals with RA are at increased risk of VTE regardless of age, sex, BMI, disease duration and exposure to exogenous oestrogens, highlighting the need to consider VTE risk in all individuals with RA.
Key Findings
Results
Individuals with RA had a significantly higher risk of VTE compared to matched controls without RA.
RA cohort comprised 23,410 individuals matched 1:4 with 93,640 controls without RA.
Adjusted hazard ratio for VTE in RA vs controls was 1.46 (95% CI 1.36, 1.56).
Data were drawn from the UK Oxford-RCGP RSC primary care database between 1999 and 2018.
Multivariable-adjusted Cox proportional hazards models were used for analysis.
Results
The relative excess risk of VTE associated with RA was higher in younger individuals compared to older individuals.
Age group 18–49 years: adjusted HR 2.13 (95% CI 1.62, 2.79).
Age group 50–69 years: adjusted HR 1.57 (95% CI 1.38, 1.78).
Age group ≥70 years: adjusted HR 1.34 (95% CI 1.14, 1.60).
Absolute risk of VTE increased with older age, but the relative excess risk compared to controls was inversely associated with age.
Results
The relative excess VTE risk associated with RA was higher in individuals with normal BMI compared to those with elevated BMI.
BMI <25 kg/m²: adjusted HR 1.66 (95% CI 1.39, 1.98).
BMI 25–30 kg/m²: adjusted HR 1.60 (95% CI 1.36, 1.88).
BMI >30 kg/m²: adjusted HR 1.41 (95% CI 1.19, 1.68).
Absolute risk of VTE increased with higher BMI, but the relative excess risk compared to controls was higher at normal BMI.
Results
VTE risk remained elevated in individuals with RA irrespective of disease duration.
Elevated VTE risk was observed across all disease duration strata examined.
This suggests that VTE risk is not confined to any particular phase of RA disease course.
Disease duration was examined as a stratification variable in the Cox proportional hazards analysis.
Results
VTE risk in women with RA was similar regardless of prescription of oestrogen-containing contraceptives, but was higher in women with RA prescribed HRT compared to those not prescribed HRT.
Women prescribed oestrogen-containing contraceptives showed similar VTE risk compared to those not prescribed such contraceptives.
Women with RA prescribed hormone replacement therapy (HRT) had higher VTE risk than those with RA not prescribed HRT.
Exposure to exogenous oestrogens via HRT appeared to interact with RA-associated VTE risk.
Analyses were stratified by prescription of oestrogen-containing contraceptives or HRT.
Russell M, Bechman K, Gibson M, Basey V, Mclean M, Rana S, et al.. (2025). Risk of venous thromboembolism in people with RA: a population-based study in the UK.. Rheumatology (Oxford, England). https://doi.org/10.1093/rheumatology/keaf430