Abstract
Incidence of venous thromboembolism (VTE) in Asian population is known to be significantly lower than that in Western population. However, Recent studies from Asia have indicated that the incidence rate of VTE is as high as that in Western population under certain circumstances such as surgery, suggesting that VTE has become a disease of major concern in Asian population. Therefore, data regarding the incidence of VTE and annual change in its incidence are of a crucial importance to understand the influence of VTE on social and medical aspects of Asian population at present and in the future.
The objective of the present study was to evaluate annual age- and sex- adjusted incidence rate (ASR) of VTE from 2009 to 2013 in South Korea. In addition, annual change in pattern of VTE treatment over the study period was estimated.
South Korea has a compulsory public health insurance coverage system and the National Health Insurance (NHI) service basically covers the whole population living in Korea. Health Insurance Review and Assessment Service (HIRA) is a government-operated organization that builds review and quality assessment system for claims for NHI. All claims data that healthcare service providers submit to HIRA to be reimbursed for a service provided to patient are collected by HIRA, making a nationwide population study feasible. Using the HIRA database, VTE cases from 2009 to 2013 were identified. A VTE case was defined if both diagnostic and medication codes were identified simultaneously in a patient. Coexisting medication codes for unfractionated heparin, low-molecular-weight heparin (LMWH), or direct oral anticoagulant (DOAC; rivaroxaban) were mandatory to verify accurate detection of the VTE. To analyze pattern of VTE treatment, all medical codes of anticoagulants approved for VTE treatment in Korea prescribed within 6 months after the time of VTE diagnosis were collected. In addition, codes of procedures including thrombectomy, thromboplasty, thrombolysis, and placement of inferior vena cava filter recorded from -1 to +6 months of the time of VTE diagnosis were searched. The proportion of cancer-associated VTE, who had diagnostic codes of both cancer and VTE was analyzed.
Among 63,184 annual index cases of VTE from 2009 January to 2013 December, incidence rate of VTE was increased yearly. It was significantly higher in older population compared to that in younger population and higher in females compared to that in males. In 2009, ASRs of VTE, deep vein thrombosis (DVT), and pulmonary embolism (PE) were from 21.3, 8.1, and 13.2 per 100,000, respectively. They were increased to 29.2, 12.7, and 16.6 per 100,000, respectively, in 2013 (Table).
Prescription rates of warfarin and LMWH were significantly decreased with the introduction of DOAC between 2012 and 2013 (Figure). It might be influenced by benefits of lower cost of rivaroxaban reimbursed by NHI service for 6 months of treatment duration. Although ASR itself was increased, proportions of subjects who received mechanical procedures were decreased annually. Cancer associated VTE accounted for 33.1% of all VTE and they had higher relapse rate compared to those who did not have a diagnostic code of cancer (7.08% vs. 6.54%; p < 0.013).
Our near a whole nationwide epidemiologic study shows that ASR of VTE in Korea has continuously increased from 2009 to 2013. The result reflects a rapid aging society, improved awareness of VTE, and improved survival of patients with cancer and other morbidities that complicate VTE. The introduction and reimbursement of DOAC resulted in significant change in the pattern of anticoagulant prescription within a short period of time.
No relevant conflicts of interest to declare.
