Danish study finds more elderly and patients with comorbidities being diagnosed.

Key Takeaway

  • Analysis of nationwide data suggests a significant increase in age- and sex- standardized hospitalisation rates of first-time venous thromboembolism (VTE), due to a marked increase in rate of pulmonary embolism, in Denmark within the last decade.
  • This increase could reflect both, a real increase in the incidence of VTE and increased diagnostic awareness.
  • Additionally, risk profile of this patient population with VTE has changed temporally with more elderly and patients with comorbidities being diagnosed.

Why This Matters

  • These findings resemble previously reported evidence from Tromsø cohort study (1996–2012) and Worcester VTE-study (1985–2009).
  • This strongly indicates that the observed development in VTE incidence most likely represents a real and widespread phenomenon.

Study Design

  • This population-based study identified 67,426 patients (age, ≥18 years) with a first-time VTE hospitalisation at any Danish hospital between 2006 and 2015 from the Danish National Patient Registry.
  • Age- and sex-standardised yearly hospitalisation rates for first-time VTE were calculated.
  • 57.3% of patients (n=38,656) redeemed an anticoagulant drug prescription within 30 days of first VTE diagnosis.
  • Funding: Bristol-Myers Squibb/Pfizer.

Key Results

  • The age- and sex-standardised hospitalisation rate of first time VTE increased from 12.6 (95% CI, 12.3–12.9) per 10,000 person-years at risk in 2006 to 15.1 (95% CI, 14.7–15.4) per 10,000 person-years at risk in 2015, corresponding to a 19.8% increase in the rate of VTE.
  • First-time hospitalisation for pulmonary embolism increased by 73.9% whereas for deep vein thrombosis dropped by 11.8%.
  • Similar time trends were observed in analysis limited to patients whose validity of VTE diagnosis was supported by ≥1 filled prescription for an anticoagulant.
  • The risk profile of patients changed during the study period:
    • mean age in the overall VTE population increased from 63.5 (standard deviation [SD], 17.2) years in 2006 to 65.7 (SD, 16.5) years in 2015,
    • comorbidity burden increased with proportion of patients with a Charlson's Comorbidity Index score of ≥1 increasing from 29.0% in 2006 to 46.0% in 2015.
  • Diagnostic work seemed to change during the study period with:
    • proportion of patients being examined with CT scanning or pulmonary angiography increased from 13.9% to 42.8%,
    • use of ventilation/perfusion lung scan dropped from 22.5% to 15.5%.


  • Only VTE events leading to hospitalisation were included.
  • Lack of data for use of oral contraceptives.
  • Some cases of pulmonary embolism might have been missed because of low autopsy rates in Denmark.
  • Possible misclassification of VTE diagnosis in administrative registries.
    1. Münster AM, Rasmussen TB, Falstie-Jensen AM, Harboe L, Stynes G, Dybro L, Hansen ML, Brandes A, Grove EL, Johnsen SP. A changing landscape: Temporal trends in incidence and characteristics of patients hospitalized with venous thromboembolism 2006-2015. Thromb Res. 2019;176:46-53. doi: 10.1016/j.thromres.2019.02.009. PMID: 30776687

MAT-BH-2200333/v2/Apr 2024