Epidemiology of Venous Thromboembolism and Treatment Pattern of Oral Anticoagulation in Korea, 2009-2016: a Nationwide Study Based on the National Health Insurance Service Database

Characteristics of factor V and protein C based on results from Korean testing centers

OBJECTIVE

The global incidence of thrombosis is increasing. However, research on thrombosis in the context of Korea is scarce. We aimed to analyze the relationship between factor V and protein C test results and thrombosis in Koreans through a domestic commissioned testing institution conducting mass examinations.

METHODS

Results of factor V and protein C tests of 1386 individuals referred simultaneously to EONE Laboratories (Incheon, Republic of Korea) from January 2017 to July 2023 were analyzed retrospectively to identify the association with thrombotic disease. The tests were performed using a STAR MAX (Diagnostica Stago, Asnieres, France) automatic blood coagulation analyzer. The results were analyzed by age and sex.

RESULTS

The inspection rate increased gradually from 2017 to 2022. Women (70.0%) demonstrated a higher test rate than did men (30.0%). Young women reported high test rates; the test rate and age distribution differed by sex. Women aged between 20 and 49 years reported lower factor V and higher protein C concentrations than did men between 20 and 49 years of age.

CONCLUSIONS

The tests were more commonly performed in women than in men. Women aged between 20 and 49 years reported lower factor V concentrations and higher protein C concentrations than men between 20 and 49 years of age. This study will facilitate recognizing and preventing thrombotic diseases in women.

Dynamic Patterns and Persistence of Anticoagulation Therapy in Patients with Venous Thromboembolism in South Korea: A Nationwide Cohort Study

BACKGROUND

 Venous thromboembolism (VTE) is associated with increased morbidity, mortality, and health care expenditure. However, the comprehensive utilization of anticoagulation therapy in patients with VTE, especially regarding active cancer, in real-world practice remains unclear.

OBJECTIVE

 To describe the prescription, persistence, and patterns of anticoagulation therapy among patients with VTE stratified according to active cancer.

METHODS

 Using Korean nationwide claims data, we identified an incident, treatment-naïve cohort of patients with VTE from 2013 to 2019 and classified them according to the presence/absence of active cancer. We explored the secular trends, treatment patterns (e.g., discontinuation, interruption, and switch), and persistence of anticoagulation therapy.

RESULTS

 There were 48,504 and 7,255 patients without and with active cancer, respectively. Non-vitamin K antagonist oral anticoagulants (NOACs) were the most common anticoagulant in both groups (65.1 and 57.9%, respectively). The prescription of NOACs increased steeply over time, regardless of active cancer, whereas parenteral anticoagulants (PACs) plateaued and warfarin decreased sharply. A heterogeneous pattern was observed between the groups without and with active cancer (3-month persistence was 60.8, 62.9, 57.2, and 3.4%, respectively; 6-month persistence was 42.3, 33.5, 25.9, and 1.2% vs. 9.9%). Median durations of continuous anticoagulant therapy for warfarin, NOAC, and PAC were 183, 147, and 3 days in nonactive cancer patients, and 121, 117, and 44 days in active cancer patients.

CONCLUSION

 Our findings suggest that there were substantial differences in persistence, patterns, and patient characteristics of anticoagulant therapy based on index anticoagulant and active cancer.

Diagnostic trends of preoperative venous thromboembolism and its clinical implications in patients who underwent surgery for degenerative spinal diseases

BACKGROUND CONTEXT

Although the risk of postoperative venous thromboembolism (VTE) in patients who undergo surgery for degenerative spinal disease has received attention, patients experiencing prolonged pain and disability while awaiting or considering surgery have not received adequate attention regarding the risk of VTE.

PURPOSE

To investigate the epidemiology of preoperative VTE in patients undergoing surgery for degenerative spinal disease.

DESIGN

Retrospective cohort study using a nationwide database.

PATIENT SAMPLE

Patients who underwent surgery for degenerative spinal disease.

OUTCOME MEASURES

Preoperative occurrence of VTE.

METHODS

Data from 2014 to 2018 were obtained from the Korean National Health Insurance claims database. The occurrence of preoperative VTE within a 1-year period divided into 12 time intervals of 30 days each was investigated. The patients were categorized into two groups based on the presence of preoperative VTE. Multivariable logistic regression analysis was conducted to identify the factors associated with preoperative VTE. To validate the relationship between degenerative spinal disease and preoperative VTE, the diagnostic trends of preoperative VTE were analyzed in accordance with the identified risk factors.

RESULTS

The overall incidence of preoperative VTE was 50 per 10,000 individuals. Multivariable analysis revealed that VTE occurred more frequently in older patients with specific medical comorbidities, particularly in those with a lumbar spinal lesion accompanied by arthritis of the hip, knee, or shoulder. We also found that the incidence rates of preoperative VTE, as well as the gradient of their increase, began to rise approximately 2 to 3 months prior to the index surgery, peaking just before the index surgery. This diagnostic trend was consistently observed in all patients irrespective of the presence of other risk factors.

CONCLUSIONS

The incidence of preoperative VTE in patients with degenerative spinal disease exhibited a sharp increase immediately before surgery, with similar rates to those of postoperative VTE. Clinicians managing patients with degenerative spinal disease should be vigilant for preoperative as well as postoperative VTE.

Real-world data emulating randomized controlled trials of non-vitamin K antagonist oral anticoagulants in patients with venous thromboembolism

BACKGROUND

Emulating randomized controlled trials (RCTs) by real-world evidence (RWE) studies would benefit future clinical and regulatory decision-making by balancing the limitations of RCT. We aimed to evaluate whether the findings from RWE studies can support regulatory decisions derived from RCTs of non-vitamin K antagonist oral anticoagulants (NOACs) in patients with venous thromboembolism (VTE).

METHODS

Five landmark trials (AMPLIFY, RE-COVER II, Hokusai-VTE, EINSTEIN-DVT, and EINSTEIN-PE) of NOACs were emulated using the South Korean nationwide claims database (January 2012 to August 2020). We applied an active comparator and new-user design to include patients who initiated oral anticoagulants within 28 days from their VTE diagnoses. The prespecified eligibility criteria, exposure (each NOAC, such as apixaban, rivaroxaban, dabigatran, and edoxaban), comparator (conventional therapy, defined as subcutaneous heparin followed by warfarin), and the definition of outcomes from RCTs were emulated as closely as possible in each separate emulation cohort. The primary outcome was identical to each trial, which was defined as recurrent VTE or VTE-related death. The safety outcome was major bleeding. Propensity score matching was conducted to balance 69 covariates between the exposure groups. Effect estimates for outcomes were estimated using the Mantel-Haenszel method and Cox proportional hazards model and subsequently compared with the corresponding RCT estimates.

RESULTS

Compared to trial populations, real-world study populations were older (range: 63-69 years [RWE] vs. 54-59 years [RCT]), with more females (55-60.5% vs. 39-48.3%) and had a higher prevalence of active cancer (4.2-15.4% vs. 2.5-9.5%). The emulated estimates for effectiveness outcomes showed superior effectiveness of NOAC (AMPLIFY: relative risk 0.81, 95% confidence interval 0.70-0.94; RE-COVER II: hazard ratio [HR] 0.60, 0.37-0.96; Hokusai-VTE: 0.49, 0.31-0.78; EINSTEIN-DVT: 0.54, 0.33-0.89; EINSTEIN-PE: 0.50, 0.34-0.74), when contrasted with trials that showed non-inferiority. For safety outcomes, all emulations except for AMPLIFY and EINSTEIN-DVT yielded results consistent with their corresponding RCTs.

CONCLUSIONS

This study revealed the feasibility of complementing RCTs with RWE studies by using claims data in patients with VTE. Future studies to consider the different demographic characteristics between RCT and RWE populations are needed.

The Risk of Venous Thromboembolism in Korean Patients with Breast Cancer: A Single-Center Experience

The relationship between cancer and venous thromboembolism (VTE) has long been described. The risk of VTE in Asian patients with breast cancer remains largely unknown. This study described the incidence and risk factors of VTE in Korean patients with breast cancer. Data were collected from a retrospective database of patients who underwent breast cancer surgery between 2011 and 2020 at a single institution. The Cox proportional-hazards model was used to identify factors associated with VTE occurrences. Among the 2246 patients with breast cancer, 48 (2.1%) developed VTE during a median follow-up period of 53 months. The average incidence of VTE was 459 per 100,000 person-years. Age ≥ 60 years, male sex, chronic kidney disease, reconstructive procedures, and stage II or higher were independent predictive factors for VTE. VTE was associated with poor disease-free survival (hazard ratio (HR), 6.140; 95% confidence interval (CI), 3.480-10.835), and overall survival (HR, 8.842; 95% CI 4.386-17.824). Most VTE events were manageable with anticoagulation; three (6.3%) patients died of VTE, despite intensive care. The incidence of VTE was significantly elevated in Korean patients with breast cancer. Since VTE has a negative effect on oncologic outcomes of breast cancer, clinicians should manage its risk throughout their lifetime.

Safety and effectiveness of anticoagulation with non-vitamin K antagonist oral anticoagulants and warfarin in patients on tuberculosis treatment

Anti-tuberculosis treatment can cause significant drug-drug interaction and interfere with effective anticoagulation. However, there is a lack of evidence and conflicting data on the optimal oral anticoagulation in patients treated for tuberculosis. We investigated the safety and effectiveness of anticoagulation with non-vitamin K antagonist oral anticoagulants (NOACs) and warfarin in patients on anti-tuberculosis treatment. Patients on concomitant oral anticoagulation and anti-tuberculosis treatment including rifampin were identified from the Korean nationwide healthcare database. Subjects were censored at discontinuation of either anticoagulation or rifampin. The outcomes of interest were major bleeding, death, and ischemic stroke. A total 2090 patients (1153 on warfarin, 937 on NOAC) were included. NOAC users, compared to warfarin users, were older, had a lower prevalence of hypertension, heart failure, ischemic stroke, and aspirin use and a higher prevalence of cancer, with no significant differences in CHA₂DS₂-VASc or HAS-BLED scores. There were 18 major bleeding events, 106 deaths, and 50 stroke events during a mean follow-up of 2.9 months. After multivariable adjustment, the use of NOAC was associated with a lower risk of incident ischemic stroke (HR 0.51, 95% CI 0.27-0.94), while there was no significant difference in risk for major bleeding or death compared with warfarin. These results suggest that NOACs have better effectiveness for stroke prevention and similar safety compared with warfarin in patients on concomitant anti-tuberculosis treatment. This is the first study assessing the safety and effectiveness of NOACs compared to warfarin in this clinical scenario.

Epidemiology and comorbidities in idiopathic pulmonary fibrosis: a nationwide cohort study

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is frequently accompanied by comorbidities, with the management of these comorbidities crucial for clinical outcomes. This study investigated the prevalence, incidence, changes over time, and clinical impact of comorbidities in IPF patients, based on nationwide claims data in South Korea.

METHODS

This retrospective cohort study utilised nationwide health claim data in South Korea between 2011 and 2019. Patients with IPF were defined as those with ICD-10 code J84.1 and Rare Intractable Disease code V236 who made at least one claim per year. Patients were classified by sex, age, pirfenidone use and burden of comorbidities, and differences among groups were determined.

RESULTS

The yearly prevalence rate of IPF increased from 7.50 to 23.20 per 100,000 people, and the yearly incidence rate increased from 3.56 to 7.91 per 100,000 person-years over time. The most common respiratory comorbidity was chronic obstructive pulmonary disease (37.34%), followed by lung cancer (3.34%), whereas the most common non-respiratory comorbidities were gastro-oesophageal reflux disease (70.83%), dyslipidaemia (62.93%) and hypertension (59.04%). The proportion of some comorbidities differed by sex, age and use of pirfenidone. The proportion of lung cancer was higher in patients treated with pirfenidone, whereas the proportion of anxiety and depression were lower in patients not treated with pirfenidone. Charlson comorbidity index ≥ 4 was associated with increases in hospitalisations and total medical costs.

CONCLUSIONS

The yearly prevalence and incidence of IPF and comorbidities in Korea increased over time. These comorbidities affected the use of pirfenidone and medical resources.

Venous thromboembolism in patients with idiopathic pulmonary fibrosis, based on nationwide claim data

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a known risk factor for venous thromboembolism (VTE). However, it is currently unknown which factors are associated with an increase of VTE in patients with IPF.

OBJECTIVES

We estimated the incidence of VTE in patients with IPF and identified clinical characteristics related to VTE in patients with IPF.

DESIGN AND METHODS

De-identified nationwide health claim data from 2011 to 2019 was collected from the Korean Health Insurance Review and Assessment database. Patients with IPF were selected if they had made at least one claim per year under the J84.1 [International Classification of Diseases and Related Health Problems, 10th Revision (ICD-10)] and V236 codes of rare intractable diseases. We defined the presence of VTE as at least one claim of pulmonary embolism and deep vein thrombosis ICD-10 codes.

RESULTS

The incidence rate per 1000 person-years of VTE was 7.08 (6.44-7.77). Peak incidence rates were noted in the 50-59 years old male and 70-79 years old female groups. Ischemic heart disease, ischemic stroke, and malignancy were associated with VTE in patients with IPF, with an adjusted hazard ratio (aHR) of 1.25 (1.01-1.55), 1.36 (1.04-1.79), and 1.53 (1.17-2.01). The risk for VTE was increased in patients diagnosed with malignancy after IPF diagnosis (aHR = 3.18, 2.47-4.11), especially lung cancer [hazard ratio (HR) = 3.78, 2.90-4.96]. Accompanied VTE was related to more utilization of medical resources.

CONCLUSION

Ischemic heart disease, ischemic stroke, and malignancy, especially lung cancer, were related to higher HR for VTE in IPF.