Safety of direct oral anticoagulants versus traditional anticoagulants in venous thromboembolism

Comparison of the pharmacokinetics and pharmacodynamics of apixaban and rivaroxaban in dogs

BACKGROUND

Comparative pharmacokinetics and pharmacodynamics (PK/PD) of apixaban and rivaroxaban have not been studied in dogs and the propensity of these drugs to cause hypercoagulability after discontinuation is unknown.

HYPOTHESIS

Compare the PK/PD of clinical dosing regimens of PO apixaban and rivaroxaban administered repeatedly to healthy dogs and assess the effect of abrupt drug discontinuation on coagulation.

ANIMALS

Six University-owned, purpose-bred, middle-aged, mixed-breed dogs (4 male, 2 female).

METHODS

Dogs were given apixaban or rivaroxaban PO at 0.5 mg/kg q12h for 7 days with a 14-day washout period between drugs. Plasma drug concentrations were quantitated, and anticoagulant effects were measured using clotting times, calibrated anti-Xa bioactivity assays, and measurements of thrombin generation. The potential for rebound hypercoagulability was assessed by measuring D-dimers, thrombin-antithrombin (TAT) complexes, and antithrombin activity after drug discontinuation.

RESULTS

Plasma drug concentrations and anti-Xa bioactivities were closely correlated for both drugs, but drug concentrations varied considerably among dogs, despite consistent dose regimens. Thrombin generation variables were significantly correlated with the anti-Xa bioactivity of both drugs and no significant differences in the effects of apixaban and rivaroxaban on thrombin generation were observed. Drug discontinuation had no effect on D-dimer concentrations. The concentration of TAT complexes decreased after apixaban discontinuation and did not change after rivaroxaban discontinuation.

CONCLUSIONS AND CLINICAL IMPORTANCE

Repeated PO administration of apixaban or rivaroxaban to healthy dogs produced comparable anticoagulant effects measured by inhibition of thrombin formation. Rebound hypercoagulability after drug discontinuation was not observed and weaning of these drugs in clinical patients might not be necessary.

Construction and optimization of a polygenic risk model for venous thromboembolism in the Chinese population

BACKGROUND

Venous thromboembolism (VTE) has both environmental and genetic risk factors. It is regulated by polygenes and multisites. The polygenic risk score (PRS) has been widely used because any single genetic biomarker failed to accurately predict the genetic risk of VTE. However, no polygenic risk model has been proposed for VTE in the Chinese population. Thus, we aimed to construct a PRS model for the first episode of VTE in the Chinese population.

METHODS

First, single nucleotide polymorphisms (SNPs) associated with VTE in genome-wide association studies, meta-analyses, and candidate gene studies were screened as variables for the PRS. The logarithm of the odds ratio was used to weight the variables. Second, a training set with simulated data from 1000 cases of VTE and 1000 controls was created with different genotypes and frequencies. Finally, we calculated the area under the receiver operating characteristic curve (AUC) to evaluate the discriminatory ability of the PRS model.

RESULTS

We screened 53 SNPs potentially associated with the first episode of VTE in the Chinese population. The AUC of the PRS-53 model (containing 53 SNPs) was 0.748 (95% confidence interval, 0.727-0.770) in the training set. From the largest weight to the smallest weight, SNPs were incrementally added to the model to calculate the AUC for model optimization. The AUC of the PRS-10 model (containing 10 SNPs) was 0.718 (95% confidence interval, 0.696-0.740), with no statistically significant difference from the AUC for the PRS-53 model.

CONCLUSIONS

The PRS-10 and PRS-53 models showed similar predictive abilities and satisfactory discriminatory power and can be used to predict the genetic risk of the first episode of VTE in the Chinese population. The simplified PRS-10 model is more efficient in clinical practice.

3-Arylidene-2-oxindoles as GSK3β inhibitors and anti-thrombotic agents

Development of novel agents that prevent thrombotic events is an urgent task considering increasing incidence of cardiovascular diseases and coagulopathies that accompany cancer and COVID-19. Enzymatic assay identified novel GSK3β inhibitors in a series of 3-arylidene-2-oxindole derivatives. Considering the putative role of GSK3β in platelet activation, the most active compounds were evaluated for antiplatelet activity and antithrombotic activity. It was found that GSK3β inhibition by 2-oxindoles correlates with inhibition of platelet activation only for compounds 1b and 5a. Albeit, in vitro antiplatelet activity matched well with in vivo anti-thrombosis activity. The most active GSK3β inhibitor 5a exceeds antiplatelet activity of acetylsalicylic acid in vitro by 10.3 times and antithrombotic activity in vivo by 18.7 times (ED₅₀ 7.3 mg/kg). These results support the promising role of GSK3β inhibitors for development of novel antithrombotic agents.

Risk and Management of Bleeding Complications with Direct Oral Anticoagulants in Patients with Atrial Fibrillation and Venous Thromboembolism: a Narrative Review

Atrial fibrillation (AF) and venous thromboembolism (VTE) are highly prevalent conditions with a significant healthcare burden, and represent the main indications for anticoagulation. Direct oral anticoagulants (DOACs) are the first choice treatment of AF/VTE, and have become the most prescribed class of anticoagulants globally, overtaking vitamin K antagonists (VKAs). Compared to VKAs, DOACs have a similar or better efficacy/safety profile, with reduced risk of intracerebral hemorrhage (ICH), while the risk of major bleeding and other bleeding harms may vary depending on the type of DOAC. We have critically reviewed available evidence from randomized controlled trials and observational studies regarding the risk of bleeding complications of DOACs compared to VKAs in patients with AF and VTE. Special patient populations (e.g., elderly, extreme body weights, chronic kidney disease) have specifically been addressed. Management of bleeding complications and possible resumption of anticoagulation, in particular after ICH and gastrointestinal bleeding, are also discussed. Finally, some suggestions are provided to choose the optimal DOAC to minimize adverse events according to individual patient characteristics and bleeding risk.

Analysis of Clinical and Laboratory Risk Factors of Post-Traumatic Intracranial Hemorrhage in Patients on Direct Oral Anticoagulants with Mild Traumatic Brain Injury: An Observational Multicenter Cohort

BACKGROUND

Assessing the risk of intracranial hemorrhage (ICH) in patients with a mild traumatic brain injury (MTBI) who are taking direct oral anticoagulants (DOACs) is challenging. Currently, extensive use of computed tomography (CT) is routine in the emergency department (ED).

OBJECTIVE

This study aims to investigate whether the clinical and laboratory characteristics presented at the ED evaluation can also estimate the risk of post-traumatic ICH in DOAC-treated patients with MTBI.

METHODS

A retrospective observational study was conducted in three EDs in Italy from January 1, 2016 to March 15, 2020. All patients treated with DOACs who were evaluated for an MTBI in the ED were enrolled. The primary outcome of the study was the presence of post-traumatic ICH in the head CT performed in the ED.

RESULTS

Of 930 patients on DOACs with MTBI who were enrolled, 6.8% (63 of 930) had a post-traumatic ICH and 1.5% (14 of 930) were treated with surgery or died as a result of the ICH. None of the laboratory factors were associated with an increased risk of ICH. On multivariate analysis, previous neurosurgical intervention, major trauma dynamic, post-traumatic loss of consciousness, post-traumatic amnesia, Glasgow Coma Scale score of 14, and evidence of trauma above the clavicles were associated with a higher risk of post-traumatic ICH. The net clinical benefit provided by risk factor assessment appears superior to the strategy of performing CT on all DOAC-treated patients.

CONCLUSIONS

Assessment of the clinical characteristics presented at ED admission can help identify DOAC-treated patients with MTBI who are at risk of ICH.

Current and emerging drug strategies for the prevention of venous thromboembolism in acutely ill medical inpatients

INTRODUCTION

Venous thromboembolism (VTE) is a common complication in patients hospitalized for acute medical illnesses. Therefore, medical inpatients require a careful VTE and bleeding risk assessment to drive optimal strategies for VTE prevention. Low molecular weight heparin and fondaparinux have long been used for inhospital prophylaxis for patients at increased risk of VTE. The selection of patients who require post-discharge prophylaxis, and the role of direct oral anticoagulants remain debated. New molecules currently under development may contribute to improve the risk benefit of VTE prevention in this setting.

AREAS COVERED

This text summarizes the evidence on approved treatments and on other drugs for the prevention of VTE in acutely ill medical patients. The main focus is on their pharmacological proprieties, clinical efficacy and safety, and the current license approved by the FDA (Food and Drug Administration) and EMA (European Medicines Agency), giving the readers a way to compare available drugs to date. The trials presented consider both inhospital and extended prophylaxis.

EXPERT OPINION

Thanks to the potentially favorable safety profile, factor XI inhibitors may play a role in the prevention of VTE in this setting. The expert opinion section discusses pharmacological properties, prophylaxis trials, and potential clinical applications of this novel class of drugs.

Secondary prevention of venous thromboembolism: Predictors and outcomes of guideline adherence in a long-term prospective cohort study

Background

Prevention of recurrent venous thromboembolism (VTE) is considered a main goal of VTE management. However, the extent to which physicians adhere to the recommendations from evidence-based guidelines is unknown.

Aim

From a large, prospective clinical cohort, we aimed to (1) quantify the adherence of treatment recommendations to evidence-based guidelines and establish its predictors, and (2) estimate its impact on clinical outcomes and costs in patients with VTE.

Methods

We included 6'243 consecutive patients with VTE treated at the university outpatient unit. Detailed clinical characteristics and treatment recommendations were recorded. Adherence of treatment recommendations to evidence-based guidelines at risk assessment was assessed in terms of duration of anticoagulant treatment. Data on death were obtained from the Swiss Central Compensation Office. Health care claims data recorded between 2014 and 2019 were retrieved from Helsana, one of the largest Swiss health insurance companies.

Results

The adherence to evidence-based guidelines was 36.1%. Among patients with non-adherence, overtreatment was present in 70.1%. Significant patient-related predictors of guideline adherence were (a) age above 50 years, (b) male sex, (c) pulmonary embolism, (d) unprovoked VTE, (e) multiple VTE, (f) laboratory tests not ordered, and (g) various cardiovascular comorbidities. Non-adherence was not significantly associated with mortality, hospitalization, admission to nursing home, and costs.

Conclusions

The adherence to evidence-based guidelines was low, and several unrelated predictors appeared. Although these results need to be confirmed in other settings, they highlight the need for implementation of evidence-based guidelines in clinical practice.

Expert Recommendations on the Usage of Non-vitamin K Antagonist Oral Anticoagulants (NOACs) from India: Current Perspective and Future Direction

Non-vitamin K antagonist oral anticoagulants (NOACs) are a new class of anticoagulant drugs used in the prevention and treatment of venous thromboembolism (VTE) and atrial fibrillation (AF). Anticoagulation requires the integration of the correct type and dose of oral anticoagulants based on patient characteristic, and therefore therapy needs to be individualized for each patient. Growing scientific evidence from studies on NOACs has led to a better understanding of their benefits and safety. A large amount of available data creates a necessity for an adaptable practical document for the usage of NOACs in India. The current consensus, developed by experts from India, aims to give recommendations on various frequently raised clinical questions with regards to NOACs and its usage. This practical document provides a platform upon which future guidelines, policies, training, and education for the use of NOACs can be tailored.

Bone density and quality in patients treated with direct-acting oral anticoagulants versus warfarin

INTRODUCTION

Direct-acting oral anticoagulants (DOACs) are therapeutic alternatives to warfarin that act independently of vitamin K, thus not affecting bone matrix formation. The aim of this study was to compare bone mineral density (BMD) and microarchitecture in patients treated with DOACs versus warfarin.

METHODS

Cross-sectional, observational study in patients using oral anticoagulants for >1 year and a paired control group (CG). Based on the type of anticoagulant used, the patients were grouped into a DOAC (DOACG) or warfarin (WG) group. All patients filled out a questionnaire and underwent BMD evaluation and trabecular bone score (TBS) measurement.

RESULTS

In all, 150 patients were included (50 patients in each group). The mean age was 60.49 ± 7.48 years, and most participants were men (64%). The most frequent comorbidities were hypertension, dyslipidemia, and hyperglycemia (comparison between groups p > 0.05). Low bone mass was diagnosed in 42%, 50%, and 66% of the patients in the CG, DOACG, and WG, respectively (p = 0.012). On logistic regression analysis, BMD was associated with body mass index (BMI; odds ratio [OR] 0.846, 95% confidence interval [CI] 0.763-0.926, p = 0.001), creatinine level (OR 0.024, 95%CI 0.001-0.434, p = 0.017), and TBS value (OR 17.777, 95%CI 4.526-96.903, p = 0.000). The mean TBS decreased progressively from the CG to the DOACG and WG (1.328 ± 0.112, 1.264 ± 0.138, and 1.203 ± 0.112, respectively, p < 0.001). On multivariate linear regression, negative predictors of TBS included warfarin use (-0.06, 95%CI -0.11 to -0.02, p = 0.006), BMI (-0.01, 95%CI -0.01 to -0.00, p < 0.001), and hyperglycemia (-0.07, 95%CI -0.11 to -0.03, p = 0.003), while positive predictors were an active IPAQ classification (0.06, 95%CI 0.01-0.11, p = 0.029) and family history of hip fracture (0.07, 95%CI 0.01-0.14, p = 0.029).

CONCLUSION

Patients using anticoagulants have lower BMD and TBS values compared with controls. This negative effect on bone was more pronounced with warfarin, but was also seen with DOACs.

Development of rivaroxaban microemulsion-based hydrogel for transdermal treatment and prevention of venous thromboembolism

We have developed a microemulsion (ME)-based hydrogel, containing propylene glycol, Azone®, Labrasol®, isobutanol and water (20:3:18:3:56), for the transdermal delivery of rivaroxaban (RVX). Formulation ME-1:RVX, which was loaded with 0.3 mg/g of RVX, presented as a clear, homogenous fluid with a droplet size of 82.01 ± 6.32 nm and a PdI of 0.207 ± 0.01. To provide gelation properties, 20 % (w/w) of Pluronic® F-127 was added to ME-1:RVX to generate formulation PME-1a. An added benefit was an increased capacity for RVX to 0.4 mg/g (formulation PME-1b). PME-1b displayed spherical droplets with a nanoscale diameter as observed by Transmission Electron Microscopy. The release of RVX from PME-1b was 20.71 ± 0.76 μg/cm² with a permeation through pig epidermis of 18.32 ± 8.87 μg/cm² as measured in a Franz Cell for 24 h. PME-1b presented a pseudoplastic behavior, pH value compatible with the skin and good stability over 60 days at room and elevated temperatures. The prothrombin time was assessed for each concentration of RVX obtained in the permeation assay and each demonstrated a relevant anticoagulant activity. PME-1b also presented no cytotoxicity against HaCaT cells. Utilizing GastroPlus® software, an in silico analysis was performed to simulate the delivery of PME-1b through a transdermal system that suggested a minimum dose of RVX for the treatment and prevention of venous thromboembolism could be achieved with an 8 h administration regimen. These results suggest that PME-1b is a promising transdermal formulation for the effective delivery of RVX that could be a viable alternative for the treatment and prevention of venous thromboembolism.

Pharmacokinetics and Biologic Activity of Apixaban in Healthy Dogs

Thrombosis is common in critically ill dogs and causes considerable morbidity and mortality. The direct factor Xa inhibitor apixaban is safe, efficacious, and convenient in humans. This study aimed to determine the pharmacokinetics (PK), bioactivity, protein binding, and bioavailability of apixaban following intravenous (IV) and oral (PO) administration to healthy dogs. Six healthy, adult, mixed-breed dogs were administered apixaban 0.18 mg/kg IV and then following a minimum 2-week washout period administered apixaban 0.2 mg/kg PO. Dogs were monitored using an apixaban-calibrated anti-Xa bioassay, prothrombin time (PT) and activated partial thromboplastin time (aPTT) and tissue-factor thromboelastography (TF-TEG). Plasma apixaban concentrations were measured using liquid chromatography-tandem mass spectrometry. Concentration-time plots were constructed, and PK modeling performed using compartmental methods. Administration of IV and PO apixaban was well-tolerated. Following IV administration, mean half-life was 4.1 h, and volume of distribution was 177 ml/kg. Apixaban was highly protein bound (98.6%). Apixaban concentrations and anti-Xa activity were highly correlated (R2 0.994, P < 0.0001). Intravenous apixaban significantly prolonged PT at time points up to 1 h, and aPTT at time points up to 0.25 h post-administration. Coagulation times were positively correlated with apixaban concentrations (PT R2 0.599, P < 0.0001; aPTT R2 0.430, P < 0.0001) and TF-TEG R-time was significantly prolonged 0.25 h post-administration. Following oral administration, mean bioavailability was 28.4%, lag time was 2 h, time to Cmax was 5 h and the apparent elimination half-life was 3.1 h. Oral apixaban significantly prolonged PT at 4, 6, and 8 h but aPTT and TF-TEG were not consistently affected by oral apixaban. Apixaban concentrations are best monitored using anti-Xa activity. Future studies should determine PK and bioactivity of other doses using commercial tablets and following multidose administration and establish safe, effective dosing ranges in sick dogs.

Effectiveness of local hemostatic to prevent bleeding in dental patients on anticoagulation: A systematic review and network meta-analysis

This study aimed to determine the effectiveness of hemostatic protocols to prevent bleeding in dental procedures among individuals undergoing oral anticoagulation therapy. A systematic review and network meta-analysis were accomplished. Searches of literature and grey literature were performed in different electronic databases. Clinical trials were considered as part of the inclusion criteria. Data extraction and assessment of the risk of bias of the included articles were performed. Assessment of the certainty of evidence was also performed. As results we find that the N-butyl-2-cyanoacrylate [RR -35.00 (95% CI - 107.12, -5.78)], calcium sulfate (CaSO₄) [RR -5.62 (95% CI -11.41, -1.03)], and tranexamic acid (TXA) [RR -3.46 (95% CI -7.63, -0.77)] showed beneficial effects compared to placebo. However, only TXA presented beneficial effects with moderate certainty evidence. N-butyl-2-cyanoacrylate and CaSO₄ presented very low certainty evidence. In the comparisons between the hemostatic agents, no differences were observed. For the mean bleeding time, no significant difference in the comparisons was observed as well. Concluding, bleeding events in individuals on oral anticoagulation decreased with the use of TXA compared to placebo. N-butyl-2-cyanoacrylate and CaSO₄ were also superior to placebo, but the certainty of evidence was low. For the mean bleeding time, no significant difference in hemostatic agents was observed.

Impact of pharmacist-conducted anticoagulation patient education and telephone follow-up on transitions of care: a randomized controlled trial

Background

There is limited published data in Lebanon evaluating the impact of supplemental education for anticoagulants use, especially DOACs, on clinical outcomes such as bleeding. The study aims to assess the impact of pharmacist-conducted anticoagulation education and follow-up on bleeding and readmission rates.

Methods

This study was a randomized, non-blinded interventional study conducted between August 2017 and July 2019 in a tertiary care teaching Lebanese hospital. Participants were inpatients ≥18 years discharged on an oral anticoagulant for treatment. Block randomization was used. The control group received the standard nursing counseling while the intervention group additionally received pharmacy counseling. Phone call follow-ups were done on day 3 and 30 post-discharge. Primary outcomes included readmission rates and any bleeding event at day 3 and 30 post-discharge. Secondary outcomes included documented elements of education in the medical records and reported mortality upon day 30 post-discharge.

Results

Two hundred patients were recruited in the study (100 patients in each study arm) with a mean age of 73.9 years. In the pharmacist-counseled group, more patients contacted their physician within 3 days (14% versus 4%; p = 0.010), received explicit elements of education (p < 0.001) and documentation in the chart was better (p < 0.05). In the standard of care group, patients were more aware of their next physician appointment date (52% versus 31%, p < 0.001). No difference in bleeding rates at day 3 and 30 post-discharge was observed between the groups.

Conclusions

Although pharmacist-conducted anticoagulation education did not appear to reduce bleeding or readmission rates at day 30, pharmacist education significantly increased patient communication with their providers in the early days post-discharge.

Trial registration

Lebanon Clinical Trial Registry LBCTR2020033424. Retrospectively registered. Date of registration: 06/03/2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-021-06156-2.

New anticoagulants: Moving beyond the direct oral anticoagulants

Although anticoagulants have been in use for more than 80 years, heparin and vitamin K antagonists were the sole available options until recently. Although these agents revolutionized the prevention and treatment of thrombotic diseases, their use has been hampered by the necessity for coagulation monitoring and by bleeding complications resulting in part from their multiple sites of action. Owing to advances in basic science, animal models, and epidemiology, the arsenal of available anticoagulants has expanded in the past two decades. This evolution has yielded many novel compounds that target single coagulation enzymes. Initially, thrombin and factor Xa were targeted because of their critical roles in coagulation. However, attention has now shifted to compounds that target upstream reactions, particularly those catalyzed by factors XIIa and XIa, which are part of the contact system. This shift is predicated on epidemiological and experimental evidence suggesting that these factors are more important for thrombosis than for hemostasis. With the goal of developing a new class of anticoagulants associated with a lower risk of bleeding than currently available agents, dozens of drugs targeting the contact system are now in development. This article focuses on the rationale, development, and testing of these new agents with a concentration on those that have reached or completed phase 2 evaluation for at least one indication.

Anticoagulation in patients with atrial fibrillation and active cancer: an international survey on patient management

BACKGROUND

In patients with active cancer and atrial fibrillation (AF) anticoagulation, thrombotic and bleeding risk still entail uncertainty.

AIM

We explored the results of an international survey examining the knowledge and behaviours of a large group of physicians.

METHODS AND RESULTS

A web-based survey was completed by 960 physicians (82.4% cardiologists, 75.5% from Europe). Among the currently available anticoagulants for stroke prevention in patients with active cancer, direct oral anticoagulants (DOACs) were preferred by 62.6%, with lower values for low molecular weight heparin (LMWH) (24.1%) and for warfarin (only 7.3%). About 46% of respondents considered that DOACs should be used in all types of cancers except in non-operable gastrointestinal cancers. The lack of controlled studies on bleeding risk (33.5% of respondents) and the risk of drug interactions (31.5%) were perceived as problematic issues associated with use of anticoagulants in cancer. The decision on anticoagulation involved a cardiologist in 27.8% of cases, a cardiologist and an oncologist in 41.1%, and a team approach in 21.6%. The patient also was involved in decision-making, according to ∼60% of the respondents. For risk stratification, use of CHA2DS2-VASc and HAS-BLED scores was considered appropriate, although not specifically validated in cancer patients, by 66.7% and 56.4%, respectively.

CONCLUSION

This survey highlights that management of anticoagulation in patients with AF and active cancer is challenging, with substantial heterogeneity in therapeutic choices. Direct oral anticoagulants seems having an emerging role but still the use of LMWH remains substantial, despite the absence of long-term data on thromboprophylaxis in AF.

Treatment of Acute Venous Thromboembolism

"Acute venous thromboembolism is a common disease seen by nearly all hospitalists. The advent of low molecular weight heparin (LMWH) several decades ago ushered in the era of early hospital discharge and home treatment. More recently, the direct oral anticoagulants (DOACs) have further simplified outpatient treatment and some offer treatment without parenteral therapy. Use of DOACs for cancer-associated venous thromboembolism is emerging and is a welcome evolution of care to spare oncologic patients the burden of daily LMWH injections."

Nurses' knowledge, attitudes, and behaviors toward venous thromboembolism prophylaxis: How to do better

OBJECTIVES

To investigate the cognition of nurses on the control and treatment of venous thromboembolism in China, thereby providing suitable countermeasures for clinical venous thromboembolism prophylaxis and treatment.

METHODS

In December 2019, a total of 1121 registered nurses from a university-affiliated hospital were selected to answer the self-designed and electronic questionnaire (Wenquanxing: www.wjx.cn/), which was designed to evaluate the nurses' knowledge (21 items), attitudes (6 items), and behaviors (9 items) toward venous thromboembolism prophylaxis. Descriptive, correlation, and regression analyses were conducted for data analysis.

RESULTS

Of the included 1121 nurses, only 55.43% nurses selected 100% correct answer. The influencing factors of knowledge included the department, education, professional ranks, and venous thromboembolism nursing experience. The nurses from ICU department gained the highest score, but the nurses from pediatrics department obtained the lowest score. The nurses with higher education level and professional ranks, and nursing experiences achieved higher scores. The total positive response rate for the attitude-related items was 68.54%. Nurses were primarily concerned about the financial penalty due to the inability to complete the work (49.0%). An increasing workload is the second primary concern of nurses (40.8%). The increasing medical cost, extension of hospital stay, and exacerbation of doctor-patient conflicts were the most serious difficulties involved in venous thromboembolism prophylaxis. The total correct score rate for the behaviors was 56.19%. Nearly half of the nurses could not offer advice for venous thromboembolism patients. The nursing experience, department, and years of work were related to the scores of knowledge-related items (all P < 0.05).

CONCLUSIONS

The overall knowledge level of the nurses was not optimistic. Although their general attitude toward venous thromboembolism prophylaxis was positive, their behaviors were influenced by many factors. Administrators should, therefore, make countermeasures to deal with these problems.