To estimate the future risk and time trends of venous thromboembolism (VTE) in individuals with newly diagnosed primary Sjögren syndrome (pSS) in the general population.
Using a population database that includes all residents of British Columbia, Canada, we created a study cohort of all patients with incident SS and up to 10 controls from the general population matched for age, sex, and entry time. We compared incidence rates (IR) of pulmonary embolism (PE), deep vein thrombosis (DVT), and VTE between the 2 groups according to SS disease duration. We calculated HR, adjusting for confounders.
Among 1175 incident pSS cases (mean age 56.7 yrs, 87.6% women), the IR of PE, DVT, and VTE were 3.9, 2.8, and 5.2 per 1000 person-years (PY), respectively; the corresponding rates in the comparison cohort were 0.9, 0.8, and 1.4 per 1000 PY. Compared with non-SS individuals, the multivariable HR for PE, DVT, and VTE among SS cases were 4.07 (95% CI 2.04-8.09), 2.80 (95% CI 1.27-6.17), and 2.92 (95% CI 1.66-5.16), respectively. The HR matched for age, sex, and entry time for VTE, PE, and DVT were highest during the first year after SS diagnosis (8.29, 95% CI 2.57-26.77; 4.72, 95% CI 1.13-19.73; and 7.34, 95% CI 2.80-19.25, respectively).
These findings provide population-based evidence that patients with pSS have a substantially increased risk of VTE, especially within the first year after SS diagnosis. Further research into the involvement of monitoring and prevention of VTE in SS may be warranted.