Takeaway
- Knee or hip osteoarthritis (OA), but not hand OA, was associated with an increased risk of venous thromboembolism (VTE).
- An increased risk of VTE in knee or hip OA was partly mediated through knee or hip replacement.
Why this matters
- Findings, if confirmed by other studies, will help identify a large proportion of high-risk population for VTE given that knee and hip OA are common in older individuals.
Study design
- 3 matched cohort studies using data from The Health Improvement Network (THIN) database, UK.
- Patients with incident knee (n=20,696), hip (n=10,411) or hand (n=6329) OA were matched with up to 5 individuals without OA.
- Primary outcome: VTE (composite of pulmonary embolism and deep vein thrombosis).
- Funding: National Natural Science Foundation of China and others.
Key results
- The risk of VTE was higher in patients with knee OA vs those without (incidence rate, 2.7 vs 2.0 per 1000 person-years; adjusted HR [aHR], 1.38; 95% CI, 1.23-1.56).
- The indirect effect through knee replacement yielded an HR of 1.07 (95% CI, 1.01-1.15), explaining 24.8% of the total effect.
- Similarly, the risk of VTE was greater in patients with hip OA vs those without (incidence rate, 3.3 vs 1.8 per 1000 person-years; aHR, 1.83; 95% CI, 1.56-2.13).
- The indirect effect (HR) of hip OA on VTE through hip replacement was 1.14 (95% CI, 1.04-1.25), explaining 28.1% of its total effect on VTE.
- No significant difference was observed in VTE risk between patients with hand OA vs those without (incidence rate, 1.5 vs 1.6 per 1000 person-years; aHR, 0.88; 95% CI, 0.67-1.16).
Limitations
- Risk of misclassification bias and residual confounding.
This clinical summary originally appeared on Univadis, part of the Medscape Professional Network.
