Which is the best model to assess risk for venous thromboembolism in hospitalised patients?

Comparison of the PADUA and IMPROVE scores in assessing venous thromboembolism risk in 42,257 medical inpatients in China

Venous thromboembolism (VTE) is a major contributor to hospital mortality and disability-adjusted life-year (DALY) loss. Multiple guidelines recommend using the Padua or IMPROVE scores to stratify VTE risk in hospitalized medical patients. However, the IMPROVE score is not recommended in Chinese guidelines, and there is very little evaluation of its clinical application and effectiveness in the Chinese population. The objective of this study is to compare the efficacy of the Padua and IMPROVE scoring models for assessing VTE risk in Chinese medical inpatients. We conducted a retrospective analysis of the clinical characteristics and thrombotic risk of 42,257 medical inpatients at a tertiary hospital in Guangdong, China, between 2021 and 2022. Logistic regression was used to assess thrombotic risk factors. The Receiver Operating Characteristic (ROC) curves, Area Under the Curve (AUC), sensitivity, and specificity were employed to evaluate the performance of the two models. Of the 42,257 patients included, 948 (2.24%) experienced VTE during hospitalization. According to the Padua score, 3,7513 (88.78%) of patients were considered low risk, while 4,744 (18.22%) were classified as high risk. The IMPROVE score identified 20,744 (49.09%) of patients as low risk, 20799(49.22%) as intermediate risk, and 714(1.69%) as high risk. The AUC for the Padua score was 0.735 (95% CI: 0.717-0.753), with a sensitivity of 49.4% and specificity of 89.6%. For the IMPROVE score, the AUC was 0.711 (95% CI: 0.693-0.729), with a sensitivity of 32.5% and specificity of 99.0%. The DeLong test, used to compare the AUCs, yielded a z-value of 1.886 with a P-value of 0.059, indicating no statistical difference. When assessing VTE risk in patients with stroke, cancer, nephrotic syndrome, and critical illness (ICU/CCU stay), both scoring models showed comparable predictive performance with AUCs ranging between 0.7 and 0.8. Both the Padua score and IMPROVE score have good predictive ability for VTE events during hospitalization in medical patients. Among them, the IMPROVE score has objective assessment items, simpler operation, and more detailed risk stratification, which is beneficial for clinicians to take physical and pharmacological preventive measures at different levels.ChiCTR2200056903, February 22, retrospectively registered.

Gynecological Cancer and Venous Thromboembolism: A Narrative Review to Increase Awareness and Improve Risk Assessment and Prevention

The prevention and appropriate management of venous thromboembolism in cancer patients is of paramount importance. However, the literature data report an underestimation of this major problem in patients with gynecological cancers, with an inconsistent venous thromboembolism risk assessment and prophylaxis in this patient setting. This narrative review provides a comprehensive overview of the available evidence regarding the management of venous thromboembolism in cancer patients, focusing on the specific context of gynecological tumors, exploring the literature discussing risk factors, risk assessment, and pharmacological prophylaxis. We found that the current understanding and management of venous thromboembolism in gynecological malignancy is largely based on studies on solid cancers in general. Hence, further, larger, and well-designed research in this area is needed.

Advances and current research in primary thromboprophylaxis to prevent hospital-associated venous thromboembolism

Hospital-associated venous thromboembolism (VTE) is defined as any case of VTE occurring during hospital admission and for up to 90 days post discharge. It accounts for over 50% of all cases of VTE internationally; indeed, there are an estimated 10 million cases of hospital-associated VTE annually. Over the last decade, there has been increasing interest in improving VTE risk assessment and thromboprophylaxis. This review summarises all the recent and ongoing major research studies and future challenges in the different areas, including medical, surgical and obstetric patients, as well as special areas such as lower limb immobilisation. We include sections on both pharmacological and mechanical thromboprophylaxis.

Evaluation of venous thromboembolism risk assessment models for hospital inpatients: the VTEAM evidence synthesis

Background

Pharmacological prophylaxis during hospital admission can reduce the risk of acquired blood clots (venous thromboembolism) but may cause complications, such as bleeding. Using a risk assessment model to predict the risk of blood clots could facilitate selection of patients for prophylaxis and optimise the balance of benefits, risks and costs.

Objectives

We aimed to identify validated risk assessment models and estimate their prognostic accuracy, evaluate the cost-effectiveness of different strategies for selecting hospitalised patients for prophylaxis, assess the feasibility of using efficient research methods and estimate key parameters for future research.

Design

We undertook a systematic review, decision-analytic modelling and observational cohort study conducted in accordance with Enhancing the QUAlity and Transparency Of health Research (EQUATOR) guidelines.

Setting

NHS hospitals, with primary data collection at four sites.

Participants

Medical and surgical hospital inpatients, excluding paediatric, critical care and pregnancy-related admissions.

Interventions

Prophylaxis for all patients, none and according to selected risk assessment models.

Main outcome measures

Model accuracy for predicting blood clots, lifetime costs and quality-adjusted life-years associated with alternative strategies, accuracy of efficient methods for identifying key outcomes and proportion of inpatients recommended prophylaxis using different models.

Results

We identified 24 validated risk assessment models, but low-quality heterogeneous data suggested weak accuracy for prediction of blood clots and generally high risk of bias in all studies. Decision-analytic modelling showed that pharmacological prophylaxis for all eligible is generally more cost-effective than model-based strategies for both medical and surgical inpatients, when valuing a quality-adjusted life-year at £20,000. The findings were more sensitive to uncertainties in the surgical population; strategies using risk assessment models were more cost-effective if the model was assumed to have a very high sensitivity, or the long-term risks of post-thrombotic complications were lower. Efficient methods using routine data did not accurately identify blood clots or bleeding events and several pre-specified feasibility criteria were not met. Theoretical prophylaxis rates across an inpatient cohort based on existing risk assessment models ranged from 13% to 91%.

Limitations

Existing studies may underestimate the accuracy of risk assessment models, leading to underestimation of their cost-effectiveness. The cost-effectiveness findings do not apply to patients with an increased risk of bleeding. Mechanical thromboprophylaxis options were excluded from the modelling. Primary data collection was predominately retrospective, risking case ascertainment bias.

Conclusions

Thromboprophylaxis for all patients appears to be generally more cost-effective than using a risk assessment model, in hospitalised patients at low risk of bleeding. To be cost-effective, any risk assessment model would need to be highly sensitive. Current evidence on risk assessment models is at high risk of bias and our findings should be interpreted in this context. We were unable to demonstrate the feasibility of using efficient methods to accurately detect relevant outcomes for future research.

Future work

Further research should evaluate routine prophylaxis strategies for all eligible hospitalised patients. Models that could accurately identify individuals at very low risk of blood clots (who could discontinue prophylaxis) warrant further evaluation.

Study registration

This study is registered as PROSPERO CRD42020165778 and Researchregistry5216.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: NIHR127454) and will be published in full in Health Technology Assessment; Vol. 28, No. 20. See the NIHR Funding and Awards website for further award information.

The role of health policy in the prevention of venous thromboembolism in the UK National Health Service-Learning from the past, looking to the future

Venous thromboembolism is the third most common cause of cardiovascular death globally and many diagnoses are preventable. The UK NHS has led international efforts to reduce VTE, particularly hospital-associated VTE, through coordinated national policy action and world-leading research. Despite this, VTE remains an important cause of morbidity and mortality in the UK, as underlined by the recent COVID-19 pandemic. Future reductions in VTE incidence/deaths will require progress on several fronts: a better understanding of case mix; revisiting VTE risk assessment, focussing on thromboprophylaxis failure and improving awareness of VTE amongst clinicians and the public. Changes to healthcare delivery, with care increasingly delivered outside of hospital, alongside changing disease patterns, including the rise in obesity, have huge implications for VTE and will dramatically alter prevention. The UK, with its nationalised healthcare model and long history of policy action on VTE, provides a unique lens through which to study past successes and future priorities for VTE prevention.

Overuse and underuse of thromboprophylaxis in medical inpatients

Background

Thromboprophylaxis (TPX) prescription is recommended in medical inpatients categorized as high risk of venous thromboembolism (VTE) by validated risk assessment models (RAMs), but how various RAMs differ in categorizing patients in risk groups, and whether the choice of RAM influences estimates of appropriate TPX use is unknown.

Objectives

To determine the proportion of medical inpatients categorized as high or low risk according to validated RAMs, and to investigate the appropriateness of TPX prescription.

Methods

This is a prospective cohort study of acutely ill medical inpatients from 3 Swiss university hospitals. Participants were categorized as high or low risk of VTE by validated RAMs (ie, the Padua, the International Medical Prevention Registry on Venous Thromboembolism, simplified, and original Geneva scores). We assessed prescription of any TPX at baseline. We considered TPX prescription in high-risk and no TPX prescription in low-risk patients as appropriate.

Results

Among 1352 medical inpatients, the proportion categorized as high risk ranged from 29.8% with the International Medical Prevention Registry on Venous Thromboembolism score to 66.1% with the original Geneva score. Overall, 24.6% were consistently categorized as high risk, and 26.3% as low risk by all 4 RAMs. Depending on the RAM used, TPX prescription was appropriate in 58.7% to 63.3% of high-risk (ie, 36.7%-41.3% underuse) and 52.4% to 62.8% of low-risk patients (ie, 37.2%-47.6% overuse).

Conclusion

The proportion of medical inpatients considered as high or low VTE risk varied widely according to different RAMs. Only half of patients were consistently categorized in the same risk group by all RAMs. While TPX remains underused in high-risk patients, overuse in low-risk patients is even more pronounced.

Accuracy of efficient data methods to determine the incidence of hospital-acquired thrombosis and major bleeding in medical and surgical inpatients: a multicentre observational cohort study in four UK hospitals

OBJECTIVES

We evaluated the accuracy of using routine health service data to identify hospital-acquired thrombosis (HAT) and major bleeding events (MBE) compared with a reference standard of case note review.

DESIGN

A multicentre observational cohort study.

SETTING

Four acute hospitals in the UK.

PARTICIPANTS

A consecutive unselective cohort of general medical and surgical patients requiring hospitalisation for a period of >24 hours during the calendar year 2021. We excluded paediatric, obstetric and critical care patients due to differential risk profiles.

INTERVENTIONS

We compared preidentified sources of routinely collected information (using hospital coding data and local contractually mandated thrombosis datasets) to data extracted from case notes using a predesigned workflow methodology.

PRIMARY AND SECONDARY OUTCOME MEASURES

We defined HAT as objectively confirmed venous thromboembolism occurring during hospital stay or within 90 days of discharge and MBE as per international consensus.

RESULTS

We were able to source all necessary routinely collected outcome data for 87% of 2008 case episodes reviewed. The sensitivity of hospital coding data (International Classification of Diseases 10th Revision, ICD-10) for the diagnosis of HAT and MBE was 62% (95% CI, 54 to 69) and 38% (95% CI, 27 to 50), respectively. Sensitivity improved to 81% (95% CI, 75 to 87) when using local thrombosis data sets.

CONCLUSIONS

Using routinely collected data appeared to miss a substantial proportion of outcome events, when compared with case note review. Our study suggests that currently available routine data collection methods in the UK are inadequate to support efficient study designs in venous thromboembolism research.

TRIAL REGISTRATION NUMBER

NIHR127454.

A systematic approach to venous thromboembolism prevention: a focus on UK experience

Venous thromboembolism (VTE) remains a leading cause of preventable morbidity and mortality associated with hospitalization. Despite evidence that providing appropriate thromboprophylaxis to those at risk of VTE in hospital, recent data suggest that the delivery of thromboprophylaxis remains suboptimal across the globe, with a lack of standardization in approach to VTE prevention. This review considers the role of VTE risk assessment and interventions to improve the implementation of the VTE prevention pathway and highlights the systematic approach to VTE prevention adopted in England and its impact. Finally, the critical areas for further research and the emerging data presented during the 2022 ISTH annual congress in London, UK, are summarized.

An update on the global use of risk assessment models and thromboprophylaxis in hospitalized patients with medical illnesses from the World Thrombosis Day steering committee: Systematic review and meta-analysis

INTRODUCTION

Venous thromboembolism (VTE) is a leading cause of cardiovascular morbidity and mortality. The majority of VTE events are hospital-associated. In 2008, the Epidemiologic International Day for the Evaluation of Patients at Risk for Venous Thromboembolism in the Acute Hospital Care Setting (ENDORSE) multinational cross-sectional study reported that only approximately 40% of medical patients at risk of VTE received adequate thromboprophylaxis.

METHODS

In our systematic review and meta-analysis, we aimed at providing updated figures concerning the use of thromboprophylaxis globally. We focused on: (a) the frequency of patients with an indication to thromboprophylaxis according with individual models; (b) the use of adequate thromboprophylaxis; and (c) reported contraindications to thromboprophylaxis. Observational nonrandomized studies or surveys focusing on medically ill patients were considered eligible.

RESULTS

After screening, we included 27 studies from 20 countries for a total of 137 288 patients. Overall, 50.5% (95% confidence interval [CI]: 41.9-59.1, I2 99%) of patients had an indication to thromboprophylaxis: of these, 54.5% (95% CI: 46.2-62.6, I2 99%) received adequate thromboprophylaxis. The use of adequate thromboprophylaxis was 66.8% in Europe (95% CI: 50.7-81.1, I2 98%), 44.9% in Africa (95% CI: 31.8-58.4, I2 96%), 37.6% in Asia (95% CI: 25.7-50.3, I2 97%), 58.3% in South America (95% CI: 31.1-83.1, I2 99%), and 68.6% in North America (95% CI: 64.9-72.6, I2 96%). No major differences in adequate thromboprophylaxis use were found across risk assessment models. Bleeding, thrombocytopenia, and renal/hepatic failure were the most frequently reported contraindications to thromboprophylaxis.

CONCLUSIONS

The use of anticoagulants for VTE prevention has been proven effective and safe, but thromboprophylaxis prescriptions are still unsatisfactory among hospitalized medically ill patients around the globe with marked geographical differences.

Immune-mediated inflammatory diseases and risk of venous thromboembolism: A Mendelian randomization study

Introduction

Immune-mediated inflammatory diseases (IMIDs) have been associated with an increased risk of venous thromboembolism (VTE) in multiple observational studies. However, a direct causally relation between IMIDs and VTE remains unclear to date. Here, we used Mendelian randomization (MR) analysis to investigate causal associations between IMIDs and VTE.

Methods

We collected genetic data from published genome-wide association studies (GWAS) for six common IMIDs, specifically inflammatory bowel disease (IBD), Crohn's disease (CD), ulcerative colitis (UC), rheumatoid arthritis (RA), psoriasis (PSO), and systemic lupus erythematosus (SLE); and summary-level data for VTE, pulmonary embolism (PE), and deep vein thrombosis (DVT) from the FinnGen database. Two-sample MR analysis using inverse variance weighting (IVW) was performed to identify causal associations between IMIDs and VTE/DVT/PE, and sensitivity analyses were implemented for robustness.

Results

IVW analysis showed a causal relationship between genetically predicted UC (one type of IBD) and the risk of VTE (OR = 1.043, 95% CI: 1.013-1.073, p = 0.004) and DVT (OR = 1.088, 95% CI: 1.043-1.136, p < 0.001), but we found no evidence of causality between UC and PE (OR = 1.029, 95% CI: 0.986-1.074, p = 0.19). In addition, no associations were observed between total IBD, CD, RA, SLE, or PSO and VTE/DVT/PE. Sensitivity analysis found no evidence for horizontal pleiotropy.

Conclusion

This MR study provides new genetic evidence for the causal relationship between IMIDs and the risk of VTE. Our findings highlight the importance of active intervention and monitoring to mitigate VTE risk in patients with IBD, in particular those presenting with UC.