medwireNews: People with immune-mediated inflammatory disease (IMID) are almost 50% more likely to develop a venous thromboembolism (VTE) than those without such conditions, UK study data show.
Maya Buch (The University of Manchester) and colleagues say that their findings highlight “the need for increased awareness among clinicians.”
They add: “Although associations do not have a causal interpretation, this study refines our understanding of classical VTE risk factors in people with an IMID compared with the wider population.”
The study included 53,378 people with an IMID who were identified from a UK primary care database between 1999 and 2019 and 213,512 matched controls without an IMID. Among the people with an IMID, 44% had rheumatoid arthritis (RA), 26% had ulcerative colitis, 18% had Crohn’s disease, and 12% had psoriatic arthritis (PsA).
During a mean follow-up of 8.2 years, the researchers found that the unadjusted VTE incidence rate was significantly higher among the people with an IMID than among the controls, at 34.9 versus 21.7 cases per 10,000 person–years.
After adjustment for sociodemographic, clinical, and VTE risk factors, the individuals with an IMID had a significant 1.46-fold higher risk for VTE than the controls.
The VTE risk was greatest for people with Crohn’s disease, at a significant adjusted hazard ratio (aHR) of 1.74, followed by those with RA (aHR=1.54), and ulcerative colitis (aHR=1.27), which were also significant.
Individuals with PsA did not have a significantly increased VTE risk relative to controls, but the researchers say this is likely due to a lack of statistical power.
Writing in RMD Open, Buch and co-authors note that in a multivariate analysis, “[e]stablished risk factors for VTE had a similar prevalence in people with an IMID compared with the wider population, and similar strengths of association were observed in people with and without an IMID for higher age, being overweight or obese, thrombophilia, malignancy, and corticosteroid use.”
However, there were also some differences between the two groups in this analysis. Specifically, history of fracture (HR=1.29), chronic kidney disease (HR=1.29), current smoking (HR=1.22), alcohol abstinence (aHR=1.17), and male sex (HR=1.13) were only VTE risk factors among the people with IMIDs.
High and low platelet counts, measured at baseline and across the duration of the study, were also independent risk factors for VTE in both groups, but were more common among the people with an IMID “suggesting particular clinical utility in this group,” the investigators remark.
Buch et al conclude: “Our data provide an understanding of the contextual risk in IMID populations, and suggests considerable potential to update or augment existing VTE risk stratification decision aids such as the Wells Score with more refined multivariable prediction models incorporating routinely measured clinical patient characteristics.”
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