The age-standardized rate for venous thromboembolism (VTE) per 100,000 person-years increased from 32.8 in 2014 to 53.7 cases in 2018 (relative risk of 1.63; 95% confidence interval, 1.6–1.67). [1] 

The prevalence of preoperative VTE was 11.1% (n=23/208) in an observational study conducted between December 2010 and August 2014. [2]

VTE-related unfavorable outcomes developed in 13.1%, while 30-day all-cause mortality was 8.6%. [3] 

A study identified 95,205 patients with VTE (female, 56.8%). [1] 

The RRs for VTE incidence are 0.12 in the 10s (95% CI, 0.11–0.13; P < 0.001), 0.51 in the 20s (95% CI, 0.48–0.53; P < 0.001), but 3.03 in the 50s (95% CI, 2.94–3.13; P < 0.001), 7.66 in the 60s (95% CI, 7.44–7.90; P < 0.001), 18.48 in the 70s (95% CI, 17.95–19.04; P < 0.001), and 25.40 in the 80s or older (95% CI, 24.63–26.18; P < 0.001) age groups, compared with that of the 30s group, respectively. [1] 

The age standardized rate of 53.66 per 100,000 person-years in 2018 is a six-fold increase since 2004, and it is comparable to Asia’s highest incidence rate in Singapore. The incidence of VTE incidences in countries in Europe and North America (114–184 per 100,000) are much higher than those in Korea and Asian countries (13.8–57 per 100,000). [1] 

The study aimed to compare the characteristics of venous thromboembolic disease in Korean to Caucasian population. The Korean population was older, was less obese, and had more active cancer at baseline than the Caucasian population. Provoked venous thromboembolic disease was more common in the Korean population. And, Koreans showed less accompanying thrombophilia than Caucasians, and factor V Leiden mutations were not detected. Korean analyses comparing the effects of rivaroxaban and standard anticoagulation with primary outcomes showed a lower incidence of major bleeding, recurrent venous thromboembolic disease, and all-cause mortality with rivaroxaban. [4] 

Patients with VTE may experience leg swelling, pain, erythema and local heating, dyspnea and other symptoms, but differential diagnosis of VTE can be difficult due to: i) an overlap in symptoms associated with a hip fracture (e.g., swelling and severe pain) or ii) no presenting symptoms. [5]  VTE lesions were newly detected in 18 (26%) of the 70 patients. However, none of the patients complained of VTE-related symptoms and multidetector row computed tomography demonstrated that all VTEs were small and involved limited portion without lower leg edema or pleuroparenchymal complication. [6] 

Most of the patients (90%) had more than one risk factor for VTE and the most common risk factor was old age, followed by heart and respiratory failure. [7] 

VTE is currently diagnosed via blood test, Doppler ultrasound and CT scan, and can also be diagnosed using contrast venography. One representative blood test is the D-dimer in which a negative result means the absence of deep vein thrombosis (DVT). The D-dimer test may be used to help rule out the possibility of DVT, however, results should be interpreted carefully because a positive result may be observed in cases of liver disease, inflammation, malignant tumor, pregnancy, trauma, and even after recent surgery. [5] 

The proportion of direct oral anticoagulant (DOAC) prescriptions increased from 40.5% to 72.8%, whereas warfarin prescriptions decreased from 27% to 5.6% in 2014 and 2018. It seems that the convenience of use for patients, physician preference, and active marketing of new anticoagulants contributed to the increased use of DOAC. In particular, insurance coverage and easy access to medical institutions seem to be related to greater DOAC use in Korea than in other countries. [1] 

In the multivariate analysis, a pulse ≥110/min and respiratory rate ≥30/min were statistically significant predictors for VTE-related unfavorable outcomes. Diabetes was a significant risk factor for major bleeding. In addition, a history of malignancy, no anticoagulation treatment, and need for mechanical ventilation were significant predictors of all-cause mortality. [3] 

Genes provided in the present study with genetic variants associated with VTE were FVL (G1691A), Prothrombin (G20210A), MTHFR (C677T, A1298C), PAI-1 (4G/5G), factor VII activating protease (1601G > A), and endothelial protein C receptor (g.6936A_G, c.4600A_G). Among them, variants in FVL, Prothrombin, MTHFR, and PAI-1 showed high significance. [8] 

[1] Incidence of Venous Thromboembolism: The 3rd Korean Nationwide Study. J Korean Med Sci. 2022 May 2;37(17):e130. [2] Preoperative Prevalence of and Risk Factors for Venous Thromboembolism in Patients with a Hip Fracture. J Bone Joint Surg Am. (2016) 98: 2089-2095 [3] Risk Factors of Unfavorable Outcomes, Major Bleeding, and All-Cause Mortality in Patients with Venous Thromboembolism. Vasc Specialist Int. 2021 Dec 31;37:46. [4] Characteristics and Effect of Rivaroxaban on Venous Thromboembolism in Korean Patients Compared to Western Population: A Subgroup Analysis from XALIA(-LEA) Study. Vasc Specialist Int. 2022 Dec 27;38:33. [5] Recent Updates of the Diagnosis and Prevention of Venous Thromboembolism in Patients with a Hip Fracture.  H&P 2017;29:159-167. [6] Is Routine Thromboprophylaxis Needed in Korean Patients Undergoing Unicompartmental Knee Arthroplasty?, J Korean Med Sci. 2016 Mar;31(3):443-448. [7] Prevention of Venous Thromboembolism in Medical Intensive Care Unit: A Multicenter Observational Study in Korea. J Korean Med Sci. 2014 Nov;29(11):1572-1576. [8] Integrative analyses of genes about venous thromboembolism: An umbrella review of systematic reviews and meta-analyses. Medicine 101(43):p e31162, October 28, 2022.