The validity of ICD codes coupled with imaging procedure codes for identifying acute venous thromboembolism using administrative data

Accurately identifying incident cases of venous thromboembolism in the electronic health record: Performance of a novel phenotyping algorithm

BACKGROUND

Accurate identification of incident venous thromboembolism (VTE) for quality improvement and health services research is challenging. The purpose of this study was to evaluate the performance of a novel incident VTE phenotyping algorithm defined using standard terminologies, requiring three key indicators documented in the electronic health record (EHR): VTE diagnostic code, VTE-related imaging procedure code, and anticoagulant medication code.

METHODS

Retrospective chart reviews were conducted to assess the performance of the algorithm using a random sample of phenotype(+) and phenotype(-) diagnostic encounters from primary care practices and acute care sites affiliated with five hospitals across a large integrated care delivery system in Massachusetts. The performance of the algorithm was evaluated by calculating the positive predictive value (PPV), negative predictive value (NPV), sensitivity, and specificity, using the phenotype(+) and phenotype(-) diagnostic encounters sample and target population data.

RESULTS

Based on gold-standard manual chart review, the algorithm had a PPV of 95.2 % (95 % CI: 93.1-96.8 %), NPV of 97.1 % (95 % CI: 95.3-98.4 %), sensitivity of 91.7 % (95 % CI: 90.8-92.6 %), and specificity of 98.4 % (95 % CI: 98.1-98.6 %). The algorithm systematically misclassified a low number of specific types of encounters, highlighting potential areas for improvement.

CONCLUSIONS

This novel phenotyping algorithm offers an accurate approach for identifying incident VTE in general populations using EHR data and standard terminologies, and accurately identifies the specific encounter and date of diagnosis of the incident VTE. This approach can be used for measurement of incident VTE to drive quality improvement, research to expand the evidence, and development of quality metrics and clinical decision support to improve the diagnostic process.

Trends in Initial Anticoagulation Among US Patients Hospitalized With Acute Pulmonary Embolism 2011-2020

STUDY OBJECTIVE

Guidelines recommend low-molecular-weight heparin (LMWH) and direct oral anticoagulants (DOACs) rather than unfractionated heparin (UFH) for treatment of acute pulmonary embolism (PE) given their efficacy and reduced risk of bleeding. Using data from a large consortium of US hospitals, we examined trends in initial anticoagulation among hospitalized patients diagnosed with acute PE.

METHODS

We conducted a retrospective study of inpatient and observation cases between January 1, 2011, and December 31, 2020, among individuals aged more than or equal to 18 years treated at acute care hospitals contributing data to the Premier Healthcare Database. Included cases received a diagnosis of acute PE, underwent imaging for PE, and received anticoagulation at the time of admission. The primary outcome was the initial anticoagulant selected for treatment.

RESULTS

Among 299,016 cases at 1,045 hospitals, similar proportions received initial treatment with UFH (47.4%) and LMWH (47.9%). Between 2011 and 2020, the proportion of patients initially treated with UFH increased from 41.9% to 56.3%. Over this period, use of LMWH as the initial anticoagulant was reduced from 58.1% in 2011 to 37.3% in 2020. The proportion of cases admitted to the ICU, treated with mechanical ventilation or vasopressors, and inpatient mortality were stable. Factors most strongly associated with receipt of UFH were admission to the ICU (odds ratio [OR] 6.90; 95% confidence interval [CI] 6.31 to 7.54) or step-down unit (OR 2.30; 95% CI 2.16 to 2.45), receipt of thrombolysis (OR 4.25; 95% CI 3.09 to 5.84) or vasopressors (OR 1.83; 95% CI 1.32 to 2.54), and chronic renal disease (OR 1.67; 95% CI 1.54 to 1.81).

CONCLUSIONS

Despite recommendations that LMWH and DOACs be considered first-line for most patients with acute PE, use of UFH is common and increasing. Further research is needed to elucidate factors associated with persistent use of UFH and opportunities for deimplementation of low-value care.

Analysis of thromboembolism and prognosis in metastatic pancreatic cancer from the Tokushukai REAl‑world data project

Cancer-associated thromboembolism (CAT), including venous thromboembolism (VTE) and arterial thromboembolism (ATE), is a frequent complication of advanced pancreatic cancer. However, reports on its incidence and clinical outcomes, especially on ATE, are limited. The present study aimed to investigate the incidence of CAT and its effects on overall survival in patients with metastatic pancreatic cancer. As part of the Tokushukai REAl-world data project in Japan, 846 eligible patients with metastatic pancreatic cancer treated with first-line chemotherapy were identified between April 2010 and March 2020. Using diagnosis procedure combination data from these patients, the present study investigated the incidence of VTE, ATE and cerebral and gastrointestinal bleeding requiring hospitalization. Blood laboratory data were collected within 14 days of the start of first-line treatment, and Khorana scores were calculated. The associations between CAT complications and comorbidities, concomitant medications and prognosis were examined. Among the 846 patients, 21 (2.5) and 70 (8.3%) had VTE and ATE, respectively (including five with overlapping VTE and ATE). CAT-positive patients had a significantly higher rate of gastrointestinal bleeding events compared with CAT-negative patients [13 of 86 (15.2%) vs. 46 of 760 (6.1%); P=0.01]. CAT-positive patients had a poorer prognosis [hazard ratio (HR), 1.28; 95% confidence interval (CI), 1.01-1.62] compared with CAT-negative patients, even after adjusting for background factors (HR, 1.20; 95% CI, 0.95-1.52). Cox regression analyses showed that higher Khorana scores were associated with significantly worse prognosis. This real-world data demonstrated that the incidence rate of CAT in patients with metastatic pancreatic cancer was 10.2%, and no statistically significant differences were observed, although there was a trend toward an adverse prognosis. The Khorana score may also be useful for predicting prognosis, even in the absence of CAT. This study was registered in the UMIN Clinical Trial Registry (http://www.umin.ac.jp/ctr/index.htm; clinical trial no. UMIN000050590).

Validated administrative data based ICD-10 algorithms for chronic conditions: A systematic review

OBJECTIVE

This systematic review aimed to identify ICD-10 based validated algorithms for chronic conditions using health administrative data.

METHODS

A comprehensive systematic literature search using Ovid MEDLINE, Embase, PsycINFO, Web of Science and CINAHL was performed to identify studies, published between 1983 and May 2023, on validated algorithms for chronic conditions using administrative health data. Two reviewers independently screened titles and abstracts and reviewed full text of selected studies to complete data extraction. A third reviewer resolved conflicts arising at the screening or study selection stages. The primary outcome was validated studies of ICD-10 based algorithms with both sensitivity and PPV of ≥70 %. Studies with either sensitivity or PPV <70 % were included as secondary outcomes.

RESULTS

Overall, the search identified 1686 studies of which 54 met the inclusion criteria. Combining a previously published literature search, a total of 61 studies were included for data extraction. The study identified 40 chronic conditions with high validity and 22 conditions with moderate validity. The validated algorithms were based on administrative data from different countries including Canada, USA, Australia, Japan, France, South Korea, and Taiwan. The algorithms identified included several types of cancers, cardiovascular conditions, kidney diseases, gastrointestinal disorders, and peripheral vascular diseases, amongst others.

CONCLUSION

With ICD-10 prominently used across the world, this up-to-date systematic review can prove to be a helpful resource for research and surveillance initiatives using administrative health data for identifying chronic conditions.

Development and validation of thromboembolism diagnostic algorithms in children with cancer from real-world data

OBJECTIVE

To evaluate the accuracy of diagnostic algorithms developed using the International Classification of Diseases (ICD-9-CM and ICD-10-CA) diagnostic codes and physician billing codes for thromboembolism (TE) from health administrative data compared to chart review diagnoses of TE in children with cancer.

METHODS

Using data linkage between the Pediatric Oncology Group of Ontario Network Information System (Ontario pediatric cancer registry) and various administrative data housed at ICES, eight algorithms were developed including a single reference to one of the billing codes, multiple references with varying time intervals, and combinations of various billing codes during primary cancer therapy for the whole cohort and, for early (<04/2002) and later (≥04/2002, solely ICD-10 codes) periods. Reference standard was chart review data from prior studies (from 1990 to 2016) among children (≤19 years) with cancer and radiologically confirmed TE.

RESULTS

Records of 2056 patients diagnosed with cancer at two participating sites during study period were reviewed; 112 had radiologically confirmed TE. The algorithm with addition of anticoagulation utilization codes was the best performing algorithm (sensitivity = 0.76;specificity = 0.85). With use of ICD-10 only codes, sensitivity of the same algorithm improved to 0.84 with specificity of 0.80.

CONCLUSION

This study provides a valid approach for ascertaining pediatric TE using real-world data.

IMPACT

Research in pediatric thrombosis, especially cancer-related thrombosis, is limited mainly due to small-sized studies. Real-world data provide ready access to large and diverse populations. However, there are no validated algorithms for identifying thrombosis in real-world data for children. An algorithm based on combination of thrombosis and anticoagulation utilization codes had 76% sensitivity and 85% specificity to identify diagnosis of thrombosis in children in administrative data. This study provides a valid approach for ascertaining pediatric thrombosis using real-world data and offers a good avenue to advance pediatric thrombosis research.

Associations of blood pressure in the third trimester and risk of venous thromboembolism postpartum

Studies on the associations of blood pressure (BP) and the risk of venous thromboembolism (VTE) had been performed neither among pregnant women nor in Chinese population. This study included participants of pregnant women from a retrospective multicenter cohort, between May 2020 and April 2023. Systolic BP (SBP) and diastolic BP (DBP) of the participants were measured in the third trimester. The incidences of VTE (including deep venous thrombosis and/or pulmonary embolism) at 42 days postpartum were followed. With regards to SBP, pregnant women in the Q1 (≤114 mmHg), Q2 (115-122 mmHg), and Q4 group (≥131 mmHg) had increased risk of VTE than those in Q3 group (123-130 mmHg), with ORs 4.48 [1.69, 11.85], 3.52 [1.30, 9.59], and 3.17 [1.12, 8.99], respectively. Compared with pregnant women with the Q4 of DBP (≥85 mmHg), women of Q1 (≤71 mmHg) were found to have elevated risk of VTE (OR 2.73 [1.25, 5.96]). A one standard deviation decrease of DBP (9 mmHg) was related with 37% elevated risk of VTE (OR 1.37 [1.05, 1.79]). This study demonstrated a U-shaped association of SBP in the third trimester and VTE postpartum and inverse association of DBP in the third trimester and VTE postpartum.

Hospital policy of tranexamic acid to reduce transfusion in major non-cardiac surgery (TRACTION): protocol for a phase IV randomised controlled trial

INTRODUCTION

Tranexamic acid (TXA) is an inexpensive and widely available medication that reduces blood loss and red blood cell (RBC) transfusion in cardiac and orthopaedic surgeries. While the use of TXA in these surgeries is routine, its efficacy and safety in other surgeries, including oncologic surgeries, with comparable rates of transfusion are uncertain. Our primary objective is to evaluate whether a hospital-level policy implementation of routine TXA use in patients undergoing major non-cardiac surgery reduces RBC transfusion without increasing thrombotic risk.

METHODS AND ANALYSIS

A pragmatic, registry-based, blinded, cluster-crossover randomised controlled trial at 10 Canadian sites, enrolling patients undergoing non-cardiac surgeries at high risk for RBC transfusion. Sites are randomised in 4-week intervals to a hospital policy of intraoperative TXA or matching placebo. TXA is administered as 1 g at skin incision, followed by an additional 1 g prior to skin closure. Coprimary outcomes are (1) effectiveness, evaluated as the proportion of patients transfused RBCs during hospital admission and (2) safety, evaluated as the proportion of patients diagnosed with venous thromboembolism within 90 days. Secondary outcomes include: (1) transfusion: number of RBC units transfused (both at a hospital and patient level); (2) safety: in-hospital diagnoses of myocardial infarction, stroke, deep vein thrombosis or pulmonary embolism; (3) clinical: hospital length of stay, intensive care unit admission, hospital survival, 90-day survival and the number of days alive and out of hospital to day 30; and (4) compliance: the proportion of enrolled patients who receive a minimum of one dose of the study intervention.

ETHICS AND DISSEMINATION

Institutional research ethics board approval has been obtained at all sites. At the completion of the trial, a plain language summary of the results will be posted on the trial website and distributed in the lay press. Our trial results will be published in a peer-reviewed scientific journal.

TRIAL REGISTRATION NUMBER

NCT04803747.

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 coagulation factors VIII, IX and XI in the prediction and mediation of recurrent thrombotic events in children with non-central venous catheter deep vein thrombosis

BACKGROUND

The role of elevated coagulation factors VIII (FVIII), FIX, FXI for the prediction of recurrent thrombotic events in children after an index non-central venous catheter (non-CVC) related deep vein thrombosis (DVT) remains unclear.

OBJECTIVE

This study investigates the predictive role of FVIII, FIX, and FXI for recurrent thrombosis in children with index non-CVC DVTs, and the mediation effect of FVIII on chronic inflammation and recurrent thrombosis.

METHODS

Children aged 0-18 years diagnosed with an index non-CVC related DVT (1993-2020) were included in this single-center retrospective cohort study. Plasma levels of FVIII, FIX, FXI were measured cross-sectionally ≥30 days after the acute DVT. The association between the continuous variables FVIII, FIX, FXI and thrombosis recurrence was investigated using uni- and multivariable logistic regression, adjusting for age, sex, and chronic inflammation. Mediation analysis assessed the role of FVIII as a mediator between chronic inflammation and recurrent thrombosis. Ethics approval was obtained.

RESULTS

A total of 139 children with an index non-CVC related DVT were included. Thirty-eight (27 %) had a recurrent thrombosis at a median of 237 days (P25-P75 65-657 days) after the index DVT. In uni- and multivariable-analysis, FVIII, FIX or FXI did not predict thrombosis recurrence; However, chronic inflammation was an independent predictor. There was no evidence that FVIII mediated the effect of chronic inflammation on thrombosis recurrence.

CONCLUSION

We found no evidence that elevated FVIII, FIX or FXI predicted thrombosis recurrence, or evidence of a mediating role of FVIII. Underlying chronic inflammation predicted venous recurrent thrombotic events in this cohort.

Clinical Characteristics and Outcomes of Patients With Venous Thromboembolism Receiving Edoxaban in the Real World

BACKGROUND

The effectiveness and safety of edoxaban for venous thromboembolism (VTE) in unselected real-world patients have not been fully evaluated.

METHODS AND RESULTS

In the Japanese nationwide administrative database, we identified 6,262 VTE patients in whom edoxaban was initiated; these patients were divided into 3 groups based on their index doses: 15 mg/day (n=235), 30 mg/day (n=4,532), and 60 mg/day (n=1,495). We evaluated patient characteristics, recurrent VTEs, and a composite endpoint of intracranial hemorrhage (ICH) and gastrointestinal (GI) bleeding. Patient characteristics among the 15-, 30-, and 60-mg edoxaban groups varied widely regarding several aspects, including age (mean 81.0, 76.2, and 65.0 years, respectively) and body weight (mean 49.5, 51.8, and 70.3 kg, respectively). At 180 days, the cumulative incidence of recurrent VTEs in the 15-, 30-, and 60-mg edoxaban groups was 4.4%, 2.6%, and 1.8%, respectively, whereas that of ICH or GI bleeding was 7.3%, 5.4%, and 3.3%, respectively. Subgroup analyses showed that the cumulative incidence of ICH or GI bleeding in patients in the 15-mg edoxaban group was 3.6% for patients aged ≥80 years, 8.4% for those with a body weight <60 kg, and 31.3% for those with renal dysfunction.

CONCLUSIONS

Only a minority of patients with VTEs received a super low dose (15 mg) of edoxaban, and these patients may be at higher risk of bleeding as well as VTE recurrence.

Long-term outcomes of pulmonary embolism in children and adolescents

ABSTRACT

Knowledge regarding the long-term consequences of pulmonary embolism (PE) in children is limited. This cohort study describes the long-term outcomes of PE in children who were followed-up at a single-center institution using a local protocol that included clinical evaluation, chest imaging, echocardiography, pulmonary function tests, and cardiopulmonary exercise tests at follow-up, starting 3 to 6 months after acute PE. Children objectively diagnosed with PE at age 0 to 18 years, who had ≥6 months of follow-up were included. Study outcomes consisted of PE resolution, PE recurrence, death, and functional outcomes (dyspnea, impaired pulmonary or cardiac function, impaired aerobic capacity, and post-PE syndrome). The frequency of outcomes was compared between patients with/without underlying conditions. In total, 150 patients were included; median age at PE was 16 years (25th-75th percentile, 14-17 years); 61% had underlying conditions. PE did not resolve in 29%, recurrence happened in 9%, and death in 5%. One-third of patients had at least 1 documented abnormal functional finding at follow-up (ventilatory impairments, 31%; impaired aerobic capacity, 31%; dyspnea, 26%; and abnormal diffusing capacity of the lungs to carbon monoxide, 22%). Most abnormalities were transient. When alternative explanations for the impairments were considered, the frequency of post-PE syndrome was lower, ranging between 0.7% and 8.5%. Patients with underlying conditions had significantly higher recurrence, more pulmonary function and ventilatory impairments, and poorer exercise capacity. Exercise intolerance was, in turn, most frequently because of deconditioning than to respiratory or cardiac limitation, highlighting the importance of physical activity promotion in children with PE.

Venous thromboembolism in critically ill adult patients with hematologic malignancy: a population-based cohort study

PURPOSE

The aim of this study was to describe the incidence of venous thromboembolism (VTE) and major bleeding among hospitalized patients with hematologic malignancy, assessing its association with critical illness and other baseline characteristics.

METHODS

We conducted a population-based cohort study of hospitalized adults with a new diagnosis of hematologic malignancy in Ontario, Canada, between 2006 and 2017. The primary outcome was VTE (pulmonary embolism or deep venous thrombosis). Secondary outcomes were major bleeding and in-hospital mortality. We compared the incidence of VTE between intensive care unit (ICU) and non-ICU patients and described the association of other baseline characteristics and VTE.

RESULTS

Among 76,803 eligible patients (mean age 67 years [standard deviation, SD, 15]), 20,524 had at least one ICU admission. The incidence of VTE was 3.7% in ICU patients compared to 1.2% in non-ICU patients (odds ratio [OR] 3.08; 95% confidence interval [CI] 2.77-3.42). The incidence of major bleeding was 7.6% and 2.4% (OR 3.33; 95% CI 3.09-3.58), respectively. The association of critical illness and VTE remained significant after adjusting for potential confounders (OR 2.92; 95% CI 2.62-3.25). We observed a higher incidence of VTE among specific subtypes of hematologic malignancy and patients with prior VTE (OR 6.64; 95% CI 5.42-8.14). Admission more than 1 year after diagnosis of hematologic malignancy (OR 0.64; 95% CI 0.56-0.74) and platelet count ≤ 50 × 109/L at the time of hospitalization (OR 0.63; 95% CI 0.48-0.84) were associated with a lower incidence of VTE.

CONCLUSION

Among patients with hematologic malignancy, critical illness and certain baseline characteristics were associated with a higher incidence of VTE.

Validity of Routine Health Data To Identify Safety Outcomes of Interest For Covid-19 Vaccines and Therapeutics in the Context of the Emerging Pandemic: A Comprehensive Literature Review

Introduction

Regulatory guidance encourages transparent reporting of information on the quality and validity of electronic health record data being used to generate real-world benefit-risk evidence for vaccines and therapeutics. We aimed to provide an overview of the availability of validated diagnostic algorithms for selected safety endpoints for Coronavirus disease 2019 (COVID-19) vaccines and therapeutics in the context of the emerging pandemic prior to December 2020.

Methods

We reviewed the literature up to December 2020 to identify validation studies for various safety events of interest, including myocardial infarction, arrhythmia, myocarditis, acute cardiac injury, vasculitis/vasculopathy, venous thromboembolism, stroke, respiratory distress syndrome (RDS), pneumonitis, cytokine release syndrome (CRS), multiple organ dysfunction syndrome, and renal failure. We included studies published between 2015 and 2020 that were considered high quality assessed with QUADAS and that reported positive predictive values (PPVs).

Results

Out of 43 identified studies, we found that diagnostic algorithms for cardiovascular outcomes were supported by the highest number of validation studies (n=17). Accurate algorithms are available for myocardial infarction (median PPV 80%; IQR 22%), arrhythmia (PPV range >70%), venous thromboembolism (median PPV: 73%) and ischaemic stroke (PPV range ≥85%). We found a lack of validation studies for less common respiratory and cardiac safety outcomes of interest (eg, pneumonitis and myocarditis), as well as for COVID-specific complications (CRS, RDS).

Conclusion

There is a need for better understanding of barriers to conducting validation studies, including data governance restrictions. Regulatory guidance should promote embedding validation within real-world EHR research used for decision-making.

Trajectories of Oral Anticoagulation Adherence and Associated Clinical Outcomes During Long-Term Anticoagulation Among Medicare Beneficiaries With Venous Thromboembolism

BACKGROUND

Little is known about anticoagulation medication nonadherence patterns impacting effectiveness and safety outcomes in clinical practice.

OBJECTIVE

We identified adherence trajectories of extended therapy with direct-acting oral anticoagulants (DOACs) and warfarin after 6 months initial anticoagulant therapy among Medicare beneficiaries with venous thromboembolism (VTE). We further assessed the associated recurrent VTE and major bleeding risks.

METHODS

Using group-based trajectory models, this retrospective cohort study identified distinct beneficiary subgroups with similar adherence patterns of extended-phase anticoagulant treatment (DOACs or warfarin) for patients with VTE who completed 6 months of initial anticoagulant treatment. We examined associations between adherence trajectories and risks of recurrent VTE and major bleeding using inverse probability treatment weighted Cox proportional hazards models.

RESULTS

Compared with no extended treatment, consistently high DOAC adherence was associated with decreased recurrent VTE risk (hazard ratio [HR] = 0.33, 95% confidence interval [CI] = 0.21-0.51) without increased major bleeding risk, and consistently high warfarin adherence was associated with decreased recurrent VTE risk (HR = 0.62, 95% CI = 0.40-0.95) and increased major bleeding risk (HR = 1.64, 95% CI = 1.12-2.41). Gradually declining adherence to DOACs (HR = 1.80, 95% CI = 1.07-3.03) or warfarin (HR = 2.34, 95% CI = 1.57-3.47) was associated with increased bleeding risk with no change in recurrent VTE risk.

CONCLUSION AND RELEVANCE

This real-world evidence suggests persistently adhering to extended DOAC therapy is associated with lower recurrent VTE risk without increasing major bleeding among Medicare beneficiaries with VTE. Persistently adhering to extended warfarin therapy was associated with lower recurrent VTE risk but higher major bleeding risk.

Trajectories of adherence to extended treatment with direct oral anticoagulants and risks of recurrent venous thromboembolism and major bleeding

BACKGROUND: Little is known about medication adherence patterns and their association with effectiveness and safety among patients with venous thromboembolism (VTE) receiving direct oral anticoagulant (DOAC) therapy beyond 3-6 months of initial treatment. OBJECTIVE: To examine the associations between adherence trajectories of extended treatment with DOAC and the risks of recurrent VTE and major bleeding among patients with VTE. METHODS: We conducted a retrospective cohort study of patients with incident VTE who completed 6 months of initial anticoagulant treatment and received either DOAC extended therapy or no extended therapy using MarketScan Commercial and Medicare Supplemental databases (2013-2019). We used group-based trajectory models to identify distinct adherence patterns during extended treatment. Using inverse probability treatment weighted Cox proportional hazards models, we examined the association between the adherence trajectories and the risks of recurrent VTE and major bleeding. RESULTS: Among 10,960 patients with extended treatment with DOACs (rivaroxaban, apixaban, dabigatran, edoxaban) and 5,133 patients with no extended treatment, we identified 4 distinct trajectories (consistently high, gradually declining, rapidly declining, and no extended treatment). Compared with the no extended treatment group, the groups with consistently high adherence (hazard ratio = 0.09, 95% CI = 0.05-0.17) and with gradually declining adherence (0.13, 0.03-0.53) showed decreased recurrent VTE risk without increased major bleeding risk (consistently high adherence 1.19, 0.71-1.99; gradually declining adherence 1.96, 0.81-4.70). There was no difference in the risk of recurrent VTE (0.34, 0.10-1.16) for the group with rapidly declining adherence, but this group was associated with increased major bleeding risk (2.65, 1.01-6.92). CONCLUSIONS: Our findings underscore the clinical importance of continuing and remaining adherent to extended DOAC treatment without increased major bleeding risk for patients with VTE. DISCLOSURES: This research was supported by the BMS/Pfizer Alliance American Thrombosis Investigator Initiated Research Program. The funding source had no role in the design, collection, analysis, or interpretation of the data or the decision to submit the article for publication. Dr Lo-Ciganic reported receiving research funding from Merck Sharp & Dohme Corp. Dr Dietrich reported receiving honorarium for training and education from BMS/Pfizer. Dr DeRemer is a stockholder of Portola Pharmaceuticals and reported receiving personal fees for advisory board meeting from BMS. No other disclosures were reported.

Venous Thromboembolism After COVID-19 Infection Among People With and Without Immune-Mediated Inflammatory Diseases

Importance

Immune-mediated inflammatory diseases (IMIDs) and COVID-19 are independently associated with venous thromboembolisms (VTEs).

Objective

To determine if individuals with IMIDs are at higher risk of VTE following COVID-19 infection compared with individuals without IMIDs.

Design, Setting, and Participants

Population-based matched cohort study using multiple deterministically linked health administrative databases from Ontario, Canada, and including patients testing positive for COVID-19 between January 1, 2020, and December 30, 2021, and followed up until March 31, 2022. Individuals with IMIDs (n = 28 440) who tested positive for COVID-19 were matched with up to 5 individuals without an IMID (n = 126 437) who tested positive for COVID-19. Matching was based on year of birth, sex, neighborhood income, and rural/urban residence. Data analysis was performed from August 6, 2022, to August 21, 2023.

Exposure

Diagnosis of an IMID, identified using algorithms based on diagnostic codes, procedures, and specialist visits.

Main Outcome and Measure

The main outcome was estimated age- and sex-standardized incidence of VTE. Proportional cause-specific hazard models compared the risk of VTE in people with and without IMIDs. Death was a competing risk. Models adjusted for history of VTE, 2 or more doses of a COVID-19 vaccine 14 or more days prior to COVID-19 diagnosis, and the Charlson Comorbidity Index. Routinely collected health data were used, so the hypothesis tested was formulated after data collection but prior to being granted access to data.

Results

The study included 28 440 individuals (16 741 [58.9%] female; 11 699 [41.1%] male) with an IMID diagnosed prior to first COVID-19 diagnosis, with a mean (SD) age of 52.1 (18.8) years at COVID-19 diagnosis. These individuals were matched to 126 437 controls without IMIDs. The incidence of VTE within 6 months of COVID-19 diagnosis among 28 440 individuals with an IMID was 2.64 (95% CI, 2.23-3.10) per 100 000 person-days compared with 2.18 (95% CI, 1.99-2.38) per 100 000 person-days among 126 437 matched individuals without IMIDs. The VTE risk was not statistically significantly different among those with vs without IMIDs (adjusted hazard ratio, 1.12; 95% CI, 0.95-1.32).

Conclusions and Relevance

In this retrospective population-based cohort study of individuals with IMIDs following COVID-19, individuals with IMIDs did not have a higher risk of VTE compared with individuals without an IMID. These data provide reassurance to clinicians caring for individuals with IMIDs and COVID-19.

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.

Risk of venous thromboembolism or hemorrhage among individuals with chronic kidney disease on prophylactic anticoagulant after hip or knee arthroplasty

Chronic kidney disease (CKD) confers a high risk of thrombosis and bleeding. However, little evidence exists regarding the optimal choice of postoperative thromboprophylaxis in these patients. We conducted a population-based, retrospective cohort study among adults ≥66 years old with CKD undergoing hip or knee arthroplasty who had filled an outpatient prophylactic anticoagulant prescription between 2010 and 2020 in Ontario, Canada. The primary outcomes of venous thrombosis (VTE) and hemorrhage were identified by validated algorithms using relevant diagnoses and billing codes. Overlap-weighted cause-specific Cox proportional hazard models were used to examine the association of direct oral anticoagulants (DOAC) on the 90-day risk of VTE and hemorrhage compared with low-molecular-weight heparin (LMWH). A total of 27  645 patients were prescribed DOAC (N = 22  943) or LMWH (N = 4702) after arthroplasty. Rivaroxaban was the predominant DOAC (94.5%), while LMWH mainly included enoxaparin (67%) and dalteparin (31.5%). DOAC users had higher eGFRs, fewer co-morbidities, and surgery in more recent years compared to LMWH users. After weighing, DOAC (compared with LMWH) was associated with a lower risk of VTE (DOAC: 1.5% vs. LMWH: 2.1%, weighted hazard ratio [HR] 0.75, 95% confidence interval [CI] 0.59-0.94) and a higher risk of hemorrhage (DOAC: 1.3% vs. LMWH: 1.0%, weighted HR 1.44, 95% CI 1.04-1.99). Additional analyses including a more stringent VTE defining algorithm, different eGFR cut-offs, and limiting to rivaroxaban and enoxaparin showed consistent findings. Among elderly adults with CKD, DOAC was associated with a lower VTE risk and a higher hemorrhage risk compared to LMWH following hip or knee arthroplasty.

Association between serum alkaline phosphatase levels in late pregnancy and the incidence of venous thromboembolism postpartum: a retrospective cohort study

Background

Two previous studies found alkaline phosphatase (ALP) levels were related with the development of venous thromboembolism (VTE) in hospitalised patients. VTE is a leading cause of death during pregnancy and postpartum. No prior study has investigated the associations of ALP levels and VTE postpartum, and the related mechanisms remain unclear. This study aimed to investigate the associations between ALP levels and VTE postpartum, and to reveal the potential mechanisms.

Methods

In this retrospective cohort study, we included pregnant women who planned to deliver at the Department of Obstetrics and Gynecology in the three designated hospitals in a multicentre cohort of pregnant women in Wuhan, China, during two recruitment periods of January 1, 2018 to December 31, 2019, and May 14, 2020 to March 25, 2022. A total of 10,044 participants with serum ALP and whole blood hemoglobin measurements in late pregnancy (median, 37 (35, 39) weeks) were enrolled. The participants' incidences of VTE (deep venous thrombosis and/or pulmonary embolism) postpartum were confirmed from the medical records. Pregnant women with new-onset VTE postpartum (within 6 weeks after delivery) were confirmed as VTE cases.

Findings

Approximately 0.8% (79/10,044) of the pregnant women were diagnosed with VTE postpartum. In the unadjusted model, pregnant women with the lowest quintile of serum ALP levels (≤116 U/L) in late pregnancy had higher risk of VTE postpartum compared with those with the highest quintile (≥199 U/L) (OR, 2.83 [1.32, 6.05]). After adjusting for covariates of demographic, life style, birth outcomes, and other liver enzymes, pregnant women with the lowest quintile of serum ALP levels (≤116 U/L) in late pregnancy had increased risk of VTE postpartum compared with those with the highest quintile (≥199 U/L) (OR, 2.48 [1.14, 5.40]). A one standard deviation decrease of ln-transformed ALP levels were associated with elevated risk of VTE postpartum (OR, 1.29 [1.02, 1.62]). Significant negative associations of ALP with VTE were found in the unadjusted and adjusted models. The negative associations between ALP and VTE remained consistent in sensitivity analyses among participants with non-GDM, single pregnancy, non-preeclampsia, non-postpartum hemorrhage, non-extremely/very preterm and cesarean delivery. Decreased serum ALP levels significantly (P < 0.05) related to decreased hemoglobin, which was significantly (P < 0.05) related to increased risk of VTE postpartum. Decreased hemoglobin significantly (P < 0.05) mediated 7.59% of ALP-associated VTE postpartum.

Interpretation

This study suggested that low serum ALP levels in late pregnancy were associated with increased risk of VTE postpartum, and the ALP-associated VTE risk may be partially mediated by hemoglobin, suggesting that serum ALP in late pregnancy could be a promising biomarker for the prediction of VTE postpartum.

Funding

The National Natural Science Foundation of China, and the Program for HUST Academic Frontier Youth Team.

Contemporary trends in mortality related to high-risk pulmonary embolism in US from 1999 to 2019

BACKGROUND

Population-based data on high-risk pulmonary embolism (PE) mortality trends in the United States (US) are scant.

OBJECTIVES

To assess current trends in US mortality related to high-risk PE over the past 21 years and determine differences by sex, race, ethnicity, age and census region.

METHODS

Data were extracted from the Centers for Disease Control and Prevention (CDC) Wide-ranging ONline Data for Epidemiologic Research (WONDER) to determine trends in age-adjusted mortality rates (AAMR) per 100,000 people, due to high-risk PE. To calculate nationwide annual trends, we assessed the average (AAPC) and annual percent change (APC) with relative 95 % confidence intervals (CIs) using Joinpoint regression.

RESULTS

Between 1999 and 2019, high-risk PE was listed as the underlying cause of death in 209,642 patients, corresponding to an AAMR of 3.01 per 100,000 people (95 % CI: 2.99 to 3.02). AAMR from high-risk PE remained stable from 1999 to 2007 [APC: -0.2 %, (95 % CI: -2.0 to 0.5, p = 0.22)] and then significantly increased [APC: 3.1 % (95 % CI: 2.6 to 3.6), p < 0.0001], especially in males [AAPC: 1.9 % (95 % CI: 1.4 to 2.4), p < 0.001 vs AAPC: 1.5 % (95 % CI: 1.1 to 2.2), p < 0.001]. AAMR increase was more pronounced in those <65 years, Black Americans, and residents of rural areas.

CONCLUSIONS

In an US population analysis, high-risk PE mortality rate increased, with racial, sex-based, and regional variations. Further studies are needed to understand root causes for these trends and to implement appropriate corrective strategies.

Relationship between the volume of cases and in-hospital mortality in patients with cardiogenic shock receiving short-term mechanical circulatory support

BACKGROUND

We examined the relationship between annual case volume at each hospital and outcome in cardiogenic shock (CS) patients receiving mechanical circulatory support (MCS) devices.

METHODS

This cross-sectional study used the Japanese nationwide database to identify patients receiving short-term MCS for CS between April 2012 and March 2020. Of 65,837 patients, 3 subcohorts were created; the intra-aortic balloon pump (IABP) alone (n = 48,643), the extracorporeal membrane oxygenation (ECMO) (n = 16,871), and the Impella cohorts (n = 696).

RESULTS

The median annual case volume was 13.5 (7.4-22.1) in the IABP alone cohort, 6.4 (3.4-11.0) in the ECMO cohort, and 7.5 (4.0-10.7) in the Impella cohort. The highest quintile for the volume of cases in the IABP alone and ECMO had the lowest in-hospital mortality (IABP alone, 25.1% in quintile 1 vs 15.2% in quintile 5; ECMO, 73.7% in quintile 1 in 67.4% in quintile 5). Adjusted ORs for in-hospital mortality decreased as case volume increased (IABP alone, 0.63 [0.58-0.68] in quintile 5; ECMO, 0.73 [0.65-0.82] in quintile 5, with the lowest quintile as reference) but did not decrease significantly in the Impella (0.90 [0.58-1.39] in tertile 3, with the lowest tertile as reference). In the continuous models with the case volume as a continuous variable, adjusted ORs for in-hospital mortality decreased to 28 IABP cases/year and 12 ECMO cases/year. They did not decrease or became almost flat above that.

CONCLUSIONS

Higher volumes of IABP and ECMO are associated with a lower mortality. There is an upper limit to the decline. Centralizing patients with refractory CS in a particular hospital might improve patient outcomes in each region.

Developing Validated Tools to Identify Pulmonary Embolism in Electronic Databases: Rationale and Design of the PE-EHR+ Study

BACKGROUND

 Contemporary pulmonary embolism (PE) research, in many cases, relies on data from electronic health records (EHRs) and administrative databases that use International Classification of Diseases (ICD) codes. Natural language processing (NLP) tools can be used for automated chart review and patient identification. However, there remains uncertainty with the validity of ICD-10 codes or NLP algorithms for patient identification.

METHODS

 The PE-EHR+ study has been designed to validate ICD-10 codes as Principal Discharge Diagnosis, or Secondary Discharge Diagnoses, as well as NLP tools set out in prior studies to identify patients with PE within EHRs. Manual chart review by two independent abstractors by predefined criteria will be the reference standard. Sensitivity, specificity, and positive and negative predictive values will be determined. We will assess the discriminatory function of code subgroups for intermediate- and high-risk PE. In addition, accuracy of NLP algorithms to identify PE from radiology reports will be assessed.

RESULTS

 A total of 1,734 patients from the Mass General Brigham health system have been identified. These include 578 with ICD-10 Principal Discharge Diagnosis codes for PE, 578 with codes in the secondary position, and 578 without PE codes during the index hospitalization. Patients within each group were selected randomly from the entire pool of patients at the Mass General Brigham health system. A smaller subset of patients will also be identified from the Yale-New Haven Health System. Data validation and analyses will be forthcoming.

CONCLUSIONS

 The PE-EHR+ study will help validate efficient tools for identification of patients with PE in EHRs, improving the reliability of efficient observational studies or randomized trials of patients with PE using electronic databases.

Development of a computable phenotype using electronic health records for venous thromboembolism in medical inpatients: the Medical Inpatient Thrombosis and Hemostasis study

Background

Accurate and efficient methods to identify venous thromboembolism (VTE) events in hospitalized people are needed to support large-scale studies. Validated computable phenotypes using a specific combination of discrete, searchable elements in electronic health records to identify VTE and distinguish between hospital-acquired (HA)-VTE and present-on-admission (POA)-VTE would greatly facilitate the study of VTE, obviating the need for chart review.

Objectives

To develop and validate computable phenotypes for POA- and HA-VTE in adults hospitalized for medical reasons.

Methods

The population included admissions to medical services from 2010 to 2019 at an academic medical center. POA-VTE was defined as VTE diagnosed within 24 hours of admission, and HA-VTE as VTE identified more than 24 hours after admission. Using discharge diagnosis codes, present-on-admission flags, imaging procedures, and medication administration records, we iteratively developed computable phenotypes for POA-VTE and HA-VTE. We assessed the performance of the phenotypes using manual chart review and survey methodology.

Results

Among 62,468 admissions, 2693 had any VTE diagnosis code. Using survey methodology, 230 records were reviewed to validate the computable phenotypes. Based on the computable phenotypes, the incidence of POA-VTE was 29.4 per 1000 admissions and that of HA-VTE was 3.6 per 1000 admissions. The POA-VTE computable phenotype had positive predictive value and sensitivity of 88.8% (95% CI, 79.8%-94.0%) and 99.1% (95% CI, 94.0%- 99.8%), respectively. Corresponding values for the HA-VTE computable phenotype were 84.2% (95% CI, 60.8%-94.8%) and 72.3% (95% CI, 40.9%-90.8%).

Conclusion

We developed computable phenotypes for HA-VTE and POA-VTE with adequate positive predictive value and sensitivity. This phenotype can be used in electronic health record data-based research.

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.

Prognosis in Patients With Cardiogenic Shock Who Received Temporary Mechanical Circulatory Support

Background

Temporary mechanical circulatory support (MCS) is often used in patients with cardiogenic shock (CS), and the type of MCS may vary by cause of CS.

Objectives

This study sought to describe the causes of CS in patients receiving temporary MCS, the types of MCS used, and associated mortality.

Methods

This study used a nationwide Japanese database to identify patients receiving temporary MCS for CS between April 1, 2012, and March 31, 2020.

Results

Of 65,837 patients, the cause of CS was acute myocardial infarction (AMI) in 77.4%, heart failure (HF) in 10.9%, valvular disease in 2.7%, fulminant myocarditis (FM) in 2.5%, arrhythmia in 4.5%, and pulmonary embolism (PE) in 2.0% of cases. The most commonly used MCS was an intra-aortic balloon pump alone in AMI (79.2%) and in HF (79.0%) and in valvular disease (66.0%), extracorporeal membrane oxygenation with intra-aortic balloon pump in FM (56.2%) and arrhythmia (43.3%), and extracorporeal membrane oxygenation alone in PE (71.5%). Overall in-hospital mortality was 32.4%; 30.0% in AMI, 32.6% in HF, 33.1% in valvular disease, 34.2% in FM, 60.9% in arrhythmia, and 59.2% in PE. Overall in-hospital mortality increased from 30.4% in 2012 to 34.1% in 2019. After adjustment, valvular disease, FM, and PE had lower in-hospital mortality than AMI: valvular disease, OR: 0.56 (95% CI: 0.50-0.64); FM: OR: 0.58 (95% CI: 0.52-0.66); PE: OR: 0.49 (95% CI: 0.43-0.56); whereas HF had similar in-hospital mortality (OR: 0.99; 95% CI: 0.92-1.05) and arrhythmia had higher in-hospital mortality (OR: 1.14; 95% CI: 1.04-1.26).

Conclusions

In a Japanese national registry of patients with CS, different causes of CS were associated with different types of MCS and differences in survival.

Prevalence and Risk Factors for Pulmonary Embolism in Pediatric Sickle Cell Disease: A National Administrative Database Study

Patients with sickle cell disease (SCD) have a high risk for venous thromboembolism which is associated with increased risk of mortality. Studies examining risk of pulmonary embolism (PE) in children with SCD are lacking. This study was conducted in children with SCD between 0-21 years of age using a nationwide administrative database in the United States- Pediatric Health Information System (PHIS) from January 2010 to June 2021. Diagnostic codes and imaging, procedure, and pharmaceutical billing codes were used to identify PE and potential clinical, demographic, and utilization risk factors. Logistic regression analyses were performed to assess association between risk factors and PE. We identified 22,631 unique patients with SCD with a median age of 10.8 years (range: <0.1-20.9). A total of 120 (0.53%) patients developed a PE with median age of 17.4 years (range: 6.6-20.9) at PE diagnosis. Patients with PE had longer hospitalization and more frequent ICU admissions than patients without PE (p < 0.001). Risk factors significantly associated with PE on multivariable analysis included older age, prior history of central venous line (CVL), acute chest syndrome, and apheresis. Mortality was not significantly different between those with and without PE. The prevalence of PE in hospitalized children with SCD was estimated to be 0.53%. Patients with PE had higher healthcare utilization characteristics. Factors significantly associated with PE suggest that the risk for PE in SCD may be related to the severity of disease state. Future trials are needed for risk stratification and PE prevention strategies in children with SCD.

Sex Differences in Outcomes of Percutaneous Pulmonary Artery Thrombectomy in Patients With Pulmonary Embolism

BACKGROUND

The sex differences in use, safety outcomes, and health-care resource use of patients with pulmonary embolism (PE) undergoing percutaneous pulmonary artery thrombectomy are not well characterized.

RESEARCH QUESTION

What are the sex differences in outcomes for patients diagnosed with PE who undergo percutaneous pulmonary artery thrombectomy?

STUDY DESIGN AND METHODS

This retrospective cross-sectional study used national inpatient claims data to identify patients in the United States with a discharge diagnosis of PE who underwent percutaneous thrombectomy between January 2016 and December 2018. We evaluated the demographics, comorbidities, safety outcomes (in-hospital mortality), and health-care resource use (discharge to home, length of stay, and hospital charges) of patients with PE undergoing percutaneous thrombectomy.

RESULTS

Among 1,128,904 patients with a diagnosis of PE between 2016 and 2018, 5,160 patients (0.5%) underwent percutaneous pulmonary artery thrombectomy. When compared with male patients, female patients showed higher procedural bleeding (16.9% vs 11.2%; P < .05), required more blood transfusions (11.9% vs 5.7%; P < .05), and experienced more vascular complications (5.0% vs 1.5%; P < .05). Women experienced higher in-hospital mortality (16.9% vs 9.3%; adjusted OR, 1.9; 95% CI, 1.2-3.0; P = .003) when compared with men. Although length of stay and hospital charges were similar to those of men, women were less likely to be discharged home after surviving hospitalization (47.9% vs 60.3%; adjusted OR, 0.7; 95% CI, 0.50-0.99; P = .04).

INTERPRETATION

In this large nationwide cohort, women with PE who underwent percutaneous thrombectomy showed higher morbidity and in-hospital mortality compared with men.

High rate of false-positive postoperative venous thromboembolism identified using hospital ICD-10 coding

The Health Roundtable, a national benchmarking body, identified our institution as an outlier with a high number of postoperative venous thromboembolism (VTE) events. We performed a retrospective study to determine the accuracy of hospital coding for the incidence and severity of postoperative VTE. Of 232 patients identified from ICD-10 coding, 52 (22.4%) were incorrectly coded. Approximately one third (n = 68) of all VTE were asymptomatic, diagnosed incidentally. Thus, coding data are inherently flawed with inaccuracy and overrepresent the true number of VTE events, with a substantial proportion of limited clinical relevance.

The association of venous thromboembolism with blood transfusion in kidney transplant patients

BACKGROUND

Red blood cell transfusion (RBCT) is common after kidney transplantation and could have pro-thrombotic effects predisposing to venous thromboembolism (VTE). The risks for developing of VTE after RBCT in kidney transplant patients are unknown.

STUDY DESIGN AND METHODS

This was a retrospective cohort study of adult kidney transplant recipients from 2002 to 2018. The exposure of interest was receipt of RBCT after transplant. Cox proportional hazards models were used to calculate hazard ratios (HR) for the outcomes of venous thromboembolism [VTE] (deep venous thrombosis [DVT] or pulmonary embolism [PE]) using RBCT as a time-varying, cumulative exposure.

RESULTS

Out of 1258 kidney transplants recipients, 468 (37%) were transfused during the study period. Seventy-nine study participants (6.3%) developed VTE, 72 DVT (5.7%), and 22 PE (1.8%). For the receipt of 1, 2, 3-5, and >5 RBCT, compared to individuals never transfused, the number of events and adjusted HR (95%CI) for VTE were 6 (6.2%) HR 1.57 (0.69-3.58), 9 (7.6%) HR 2.54 (1.30-4.96), 15 (11.9%) HR 2.73 (1.38-5.41), and 23 (18.1%) HR 5.77 (2.99-11.14) respectively; for DVT, it was 6 (6.2%) HR 1.94 (0.84-4.48), 9 (7.6%) HR 2.92 (1.44-5.94), 14 (11.1%) HR 3.29 (1.63-6.65), and 21 (16.5%) HR 6.97 (3.53-13.76), respectively. For PE, among transfused individuals, there were 14 events (3.0%) and the HR was 2.40 (1.02-5.61).

CONCLUSION

The risks for developing VTE, DVT, and PE were significantly increased in kidney transplant patients receiving RBCT after transplant. Receipt of RBCT should prompt considerations for judicious monitoring and assessment for thrombosis.

Comparative Risk of Thrombotic and Cardiovascular Events with Tofacitinib and Anti-TNF Agents in Patients with Inflammatory Bowel Diseases

BACKGROUND

Tofacitinib and inflammatory bowel disease (IBD) have been associated with increased risks for thromboembolic and cardiovascular events, but drug attributable risk is unknown.

METHODS

We conducted a retrospective cohort study in a US claims database. We identified patients with IBD by International Classification of Disease (ICD) codes, stipulated 180 days of continuous enrollment prior to tofacitinib or anti-tumor necrosis factor (TNF) initiation to determine new users. Primary outcomes were ICD codes for venous thromboembolism (VTE) and cardiovascular (CV) events. We constructed propensity score (PS)-weighted Cox proportional hazard models to estimate hazard ratios (HRs) and time-to-event outcomes comparing tofacitinib and anti-TNF. We conducted a subgroup analysis of patients ≥ 50 years.

RESULTS

We identified 305 patients with IBD initiating tofacitinib and compared them with 19,096 initiating anti-TNFs. After weighting, balance was achieved across all demographic covariates. VTE occurred in 5% of patients treated with tofacitinib and 4% of anti-TNF users; in a PS-weighted cohort, tofacitinib did not confer a significantly elevated VTE risk compared with anti-TNF therapy (HR: 1.72, 95% CI: 0.74-3.01). A major CV event (MACE) occurred in 2% of tofacitinib users and 1% of anti-TNF users; tofacitinib also did not confer a significantly elevated risk for MACE (HR: 2.50, 95% CI: 0.37-6.18). Those with a Charlson comorbidity index ≥ 2 had greater risks for thromboembolic and cardiovascular events. Similar findings were noted in patients ≥ 50 years.

CONCLUSIONS

In this large, active comparator, study, we demonstrate that tofacitinib was not associated with a higher risk of adverse thrombotic events compared with anti-TNFs in patients with IBD.

Comparative effectiveness and safety of extended anticoagulant therapy among Medicare beneficiaries with venous thromboembolism

Guidelines recommend an extended course of anticoagulation therapy for patients who experienced venous thromboembolism (VTE) without transient provocation, however, optimal duration remains uncertain. We assessed effectiveness and safety of extended use of apixaban and warfarin greater than 6 months of initial treatment in patients with VTE. We conducted a retrospective cohort study of Medicare beneficiaries aged greater than or equal to 18 years with deep vein thrombosis or pulmonary embolism. Patients were required to have initiated anticoagulants within 30 days of their first VTE diagnosis, completed 6 months of initial anticoagulant treatment, and received extended phase treatment with apixaban (the apixaban group) or warfarin (the warfarin group) or no extended therapy. Multivariable Cox proportional hazards modeling with inverse probability treatment weighting was used to compare recurrent VTE, mortality, and major bleeding risks among the three groups. Mean extended-treatment duration was up to 10 months and 14 months in apixaban and warfarin groups, respectively. Compared with no extended treatment, apixaban use was associated with decreased risks of recurrent VTE (hazard ratio [HR] = 0.08, [95% confidence interval [CI]: 0.01-0.41]) and mortality (HR = 0.37, [95% CI: 0.27-0.51]) without increased major bleeding risk (HR = 1.29, [95% CI: 0.68-2.45]); warfarin use was associated not with recurrent VTE risk change but with increased major bleeding risk (HR = 2.14, [95% CI: 1.26-3.65]) and decreased mortality risk (HR = 0.39, [95% CI: 0.29-0.51]). Compared with warfarin, apixaban use was associated with decreased recurrent VTE (HR = 0.13, [95% CI: 0.03-0.63]) and major bleeding (HR = 0.56, [95% CI: 0.32-0.98]) risks. Subgroup and sensitivity analyses (e.g., intention-to-treat) findings remained consistent. Compared with warfarin or no extended therapy, extended-apixaban use was associated with reduced risk of recurrent VTE without increased major bleeding risk. Continuing anticoagulant therapy with apixaban greater than 6 months may be effective and safe.

Comparative effectiveness and safety of edoxaban, rivaroxaban, and apixaban in patients with venous thromboembolism: A cohort study

BACKGROUND

Although several studies have compared the effectiveness and safety of rivaroxaban and apixaban in patients with venous thromboembolism (VTE), direct comparison of these drugs with edoxaban is lacking.

OBJECTIVE

We compared the effectiveness and safety of edoxaban, rivaroxaban, and apixaban in patients with VTE.

PATIENTS/METHODS

In this retrospective cohort study using a Japanese hospital administrative database, we identified three mutually exclusive groups of patients with VTE beginning treatment with edoxaban, rivaroxaban, or apixaban. Primary effectiveness outcome was recurrent VTE, and principal safety outcome was a composite of intracranial hemorrhage and gastrointestinal bleeding. Subjects were followed for up to 180 days. Baseline characteristics among groups were balanced using propensity score matching weights.

RESULTS

Three thousand three hundred sixty-nine edoxaban, 1592 rivaroxaban, and 1998 apixaban initiators were identified. There were no significant differences among the three drugs in the prevention of recurrent VTE (adjusted incidence rate ratio [aIRR], 0.77; 95% confidence interval [CI], 0.45-1.30 for edoxaban vs. rivaroxaban; aIRR, 0.92; 95% CI, 0.54-1.56 for edoxaban vs. apixaban; and aIRR, 1.20; 95% CI, 0.69-2.10 for rivaroxaban vs. apixaban), or in the risk of intracranial hemorrhage or gastrointestinal bleeding (aIRR, 1.57, 95% CI, 0.85-2.90 for edoxaban vs. rivaroxaban; aIRR, 1.30, 95% CI, 0.76-2.23 for edoxaban vs. apixaban; and aIRR, 0.83, 95% CI, 0.42-1.64 for rivaroxaban vs. apixaban).

CONCLUSIONS

In routine care, edoxaban, rivaroxaban, and apixaban appear to have similar effectiveness and safety in the treatment of VTE.

PheValuator 2.0: Methodological improvements for the PheValuator approach to semi-automated phenotype algorithm evaluation

PURPOSE

Phenotype algorithms are central to performing analyses using observational data. These algorithms translate the clinical idea of a health condition into an executable set of rules allowing for queries of data elements from a database. PheValuator, a software package in the Observational Health Data Sciences and Informatics (OHDSI) tool stack, provides a method to assess the performance characteristics of these algorithms, namely, sensitivity, specificity, and positive and negative predictive value. It uses machine learning to develop predictive models for determining a probabilistic gold standard of subjects for assessment of cases and non-cases of health conditions. PheValuator was developed to complement or even replace the traditional approach of algorithm validation, i.e., by expert assessment of subject records through chart review. Results in our first PheValuator paper suggest a systematic underestimation of the PPV compared to previous results using chart review. In this paper we evaluate modifications made to the method designed to improve its performance.

METHODS

The major changes to PheValuator included allowing all diagnostic conditions, clinical observations, drug prescriptions, and laboratory measurements to be included as predictors within the modeling process whereas in the prior version there were significant restrictions on the included predictors. We also have allowed for the inclusion of the temporal relationships of the predictors in the model. To evaluate the performance of the new method, we compared the results from the new and original methods against results found from the literature using traditional validation of algorithms for 19 phenotypes. We performed these tests using data from five commercial databases.

RESULTS

In the assessment aggregating all phenotype algorithms, the median difference between the PheValuator estimate and the gold standard estimate for PPV was reduced from -21 (IQR -34, -3) in Version 1.0 to 4 (IQR -3, 15) using Version 2.0. We found a median difference in specificity of 3 (IQR 1, 4.25) for Version 1.0 and 3 (IQR 1, 4) for Version 2.0. The median difference between the two versions of PheValuator and the gold standard for estimates of sensitivity was reduced from -39 (-51, -20) to -16 (-34, -6).

CONCLUSION

PheValuator 2.0 produces estimates for the performance characteristics for phenotype algorithms that are significantly closer to estimates from traditional validation through chart review compared to version 1.0. With this tool in researcher's toolkits, methods, such as quantitative bias analysis, may now be used to improve the reliability and reproducibility of research studies using observational data.

Effectiveness and Safety of Extended Oral Anticoagulant Therapy in Patients with Venous Thromboembolism: A Retrospective Cohort Study

Limited real-world evidence exists for effectiveness and safety of extended oral anticoagulation beyond 6 months of initial treatment in prevention of recurrent venous thromboembolism (VTE) and adverse major bleeding events among patients with VTE. Using MarketScan Commercial and Medicare Supplemental databases (2013-2019), we conducted a retrospective cohort study to compare the risk of recurrent VTE and major bleeding events during extended treatment among patients with VTE who completed the 6-month initial treatment and received extended oral anticoagulant treatment with apixaban, warfarin, or no extended treatment. Hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated using Cox proportional hazards modeling with inverse probability treatment weighting. We identified 14,818 patients with extended treatment of apixaban (n = 4,338), warfarin (n = 5,298), or no extended treatment (n = 5,182). Compared with no extended treatment, apixaban use was associated with decreased risk of recurrent VTE (HR: 0.10, 95% CI: 0.04-0.26) without increased risk of major bleeding events (HR: 1.06, 95% CI: 0.52-2.17); warfarin use was associated with decreased risk of recurrent VTE (HR: 0.23, 95% CI: 0.12-0.44) but with increased risk of major bleeding events (HR: 2.64, 95% CI: 1.51-4.59). Compared with warfarin, apixaban use was associated with decreased risk of major bleeding events (HR: 0.42, 95% CI: 0.22-0.80) but no difference in risk of recurrent VTE (HR: 0.46, 95% CI: 0.15-1.36). In a real-world clinical setting, extended anticoagulation with apixaban or warfarin was associated with decreased risk of recurrent VTE compared with no extended treatment, and apixaban had a better safety profile with fewer major bleeding events compared with warfarin among commercially insured patients with VTE.

Comparison of effectiveness and safety for low versus full dose of apixaban during extended phase oral anticoagulation in patients with venous thromboembolism

BACKGROUND

The optimal dose of apixaban therapy to prevent asecondary venous thromboembolism (VTE) event remains unconfirmed. To investigate the effects of extended phase use of apixaban (2.5 vs. 5 mg twice daily) beyond 6 months of initial treatment on the risk of recurrent VTE and major bleeding events among patients with a history of VTE.

METHODS

A retrospective cohort analysis of two large national insurance claims databases was conducted for patients diagnosed with VTE. Cox proportional hazard models after propensity score matching were used to compare the risk of recurrent VTE and major bleeding.

RESULTS

There were no detected differences in recurrent VTE or major bleeding events between patients prescribed low versus full dose apixaban.

CONCLUSION

This study provides evidence that apixaban 2.5 mg twice daily is an alternative option for extended phase therapy for risk reduction of VTE recurrence compared to apixaban 5 mg twice daily.

Prenatal electrocardiogram testing and postpartum depression: A population-based cohort study

Background

Cardiovascular symptoms in pregnancy may be a clue to psychological distress. We examined whether electrocardiogram testing in pregnant women is associated with an increased risk of subsequent postpartum depression.

Methods

We conducted a population-based cohort study of pregnant women who delivered in Ontario, Canada comparing women who received a prenatal ECG to women who did not.

Results

In total, 3,238,218 women gave birth during the 25-year study period of whom 157,352 (5%) received an electrocardiogram during prenatal care. Receiving an electrocardiogram test was associated with a one-third relative increase in the odds of postpartum depression (odds ratio 1.34; 95% confidence interval 1.29-1.39, p < 0.001).

Conclusion

The association between prenatal electrocardiogram testing and postpartum depression suggests a possible link of organic disease with mental illness, and emphasizes that cardiovascular symptoms may be a clinical clue to the presence of an underlying mood disorder.

The association between anticoagulation and adverse outcomes after a positive SARS-CoV-2 test among older outpatients: A population-based cohort study

Introduction

Anticoagulation may improve outcomes in patients with COVID-19 when started early in the course of illness.

Materials and methods

This was a population-based cohort study using linked administrative datasets of outpatients aged ≥65 years old testing positive for SARS-CoV-2 between January 1 and December 31, 2020 in Ontario, Canada. The key exposure was anticoagulation with warfarin or direct oral anticoagulants before COVID-19 diagnosis. We calculated propensity scores and used matching weights (MWs) to reduce baseline differences between anticoagulated and non-anticoagulated patients. The primary outcome was a composite of death or hospitalization within 60 days of a positive SARS-CoV-2 test. We used the Kaplan-Meier method and cumulative incidence functions to estimate risk of the primary and component outcomes at 60 days.

Results

We studied 23,159 outpatients (mean age 78.5 years; 13,474 [58.2%] female), among whom 3200 (13.8%) deaths and 3183 (13.7%) hospitalizations occurred within 60 days of the SARS-CoV-2 test. After application of MWs, the 60-day risk of death or hospitalization was 29.2% (95% CI 27.4%–31.2%) for anticoagulated individuals and 32.1% (95% CI 30.7%–33.5%) without anticoagulation (absolute risk difference [ARD], −2.9%; p = 0.005). Anticoagulation was also associated with a lower risk of death: 18.6% (95% CI 17.0%–20.2%) with anticoagulation and 20.9% (95% CI 19.7%–22.2%) in non-anticoagulated patients (ARD -2.3%; p = 0.005).

Conclusions

Among outpatients aged ≥65 years, oral anticoagulation at the time of a positive SARS-CoV-2 test was associated with a lower risk of a composite of death or hospitalization within 60 days.

Incidence of venous thromboembolism in patients with obstructive sleep apnea: a cohort study

BACKGROUND

Previous studies suggesting that obstructive sleep apnea (OSA) may be an independent risk factor for venous thromboembolism (VTE) have been limited by reliance on administrative data and lack of adjustment for clinical variables, including obesity.

RESEARCH QUESTION

Does OSA confer an independent risk of incident VTE among a large clinical cohort referred for sleep disordered breathing evaluation?

STUDY DESIGN AND METHODS

We analyzed the clinical outcomes of 31,309 patients undergoing overnight polysomnography within a large hospital system. We evaluated the association of OSA severity with incident VTE using Cox proportional hazards modeling accounting for age, sex, body mass index (BMI), and common comorbid conditions.

RESULTS

Patients were of mean age 50.4 years and 50.1% female. There were 1,791 VTE events identified over a mean follow-up of 5.3 years. In age and sex-adjusted analyses, each 10 event/hr increase in the apnea hypopnea index (AHI) was associated with a 4% increase in incident VTE risk (hazard ratio [HR] 1.04, 95% confidence interval [CI] 1.02-1.05). After adjusting for BMI, this association disappeared (HR 1.01, 95% CI 0.99-1.03). In contrast, nocturnal hypoxemia had an independent association with incident VTE. Patients with >50% sleep time spent with oxyhemoglobin saturation <90% are at 48% increased VTE risk compared to those without nocturnal hypoxemia (HR 1.48, 95% CI 1.16-1.69).

INTERPRETATION

In this large cohort, we found that patients with more severe OSA as measured by the AHI are more likely to have incident VTE. Adjusted analyses suggest that this association is explained due to confounding by obesity. However, severe nocturnal hypoxemia may be a mechanism by which OSA heightens VTE risk.

Developing and validating natural language processing algorithms for radiology reports compared to ICD-10 codes for identifying venous thromboembolism in hospitalized medical patients

BACKGROUND

Identifying venous thromboembolism (VTE) from large clinical and administrative databases is important for research and quality improvement.

OBJECTIVE

To develop and validate natural language processing (NLP) algorithms to identify VTE from radiology reports among general internal medicine (GIM) inpatients.

METHODS

This cross-sectional study included GIM hospitalizations between April 1, 2010 and March 31, 2017 at 5 hospitals in Toronto, Ontario, Canada. We developed NLP algorithms to identify pulmonary embolism (PE) and deep venous thrombosis (DVT) from radiologist reports of thoracic computed tomography (CT), extremity compression ultrasound (US), and nuclear ventilation-perfusion (VQ) scans in a training dataset of 1551 hospitalizations. We compared the accuracy of our NLP algorithms, the previously-published "simpleNLP" tool, and administrative discharge diagnosis codes (ICD-10-CA) for PE and DVT to the "gold standard" manual review in a separate random sample of 4000 GIM hospitalizations.

RESULTS

Our NLP algorithms were highly accurate for identifying DVT from US, with sensitivity 0.94, positive predictive value (PPV) 0.90, and Area Under the Receiver-Operating-Characteristic Curve (AUC) 0.96; and in identifying PE from CT, with sensitivity 0.91, PPV 0.89, and AUC 0.96. Administrative diagnosis codes and the simple NLP tool were less accurate for DVT (ICD-10-CA sensitivity 0.63, PPV 0.43, AUC 0.81; simpleNLP sensitivity 0.41, PPV 0.36, AUC 0.66) and PE (ICD-10-CA sensitivity 0.83, PPV 0.70, AUC 0.91; simpleNLP sensitivity 0.89, PPV 0.62, AUC 0.92).

CONCLUSIONS

Administrative diagnosis codes are unreliable in identifying VTE in hospitalized patients. We developed highly accurate NLP algorithms to identify VTE from radiology reports in a multicentre sample and have made the algorithms freely available to the academic community with a user-friendly tool (https://lks-chart.github.io/CHARTextract-docs/08-downloads/rulesets.html#venous-thromboembolism-vte-rulesets).

Upper-Extremity Venous Thromboembolism Following Operative Treatment of Distal Radius Fractures: An Uncommon but Dangerous Complication

PURPOSE

Distal radius fractures are the most common long bone fracture in the United States, with an estimated incidence of 640,000 cases per year. Operative fixation presents a theoretical risk factor for the development of upper-extremity venous thromboembolism (UE-VTE). Additionally, patients presenting with distal radius fracture commonly have preexisting comorbidities that further increase the risk of UE-VTE. Finally, UE-VTE is considered the highest risk for eventual development of pulmonary embolism. Despite this, scant attention has been paid to studying UE-VTE in this population. The purpose of this study was to measure the incidence of this complication and to identify possible medical factors that increased the risk of developing UE-VTE.

METHODS

We queried the Truven MarketScan Commercial Claims and Encounters Database for all patients who experienced a distal radius fracture and were subsequently treated with open reduction and internal fixation between 2012 and 2016. Patients were identified using relevant Common Procedural Terminology codes. Demographic and medical variables were tabulated. Our primary outcome was the development of ipsilateral UE-VTE or pulmonary embolism in the first 60 days after surgery.

RESULTS

The study included 24,494 patients. The mean age was 50.7 years (range, 18-91), and 58% were women. There were 79 cases (0.3%) of UE-VTE and 19 cases of pulmonary embolism in the study population (24.1% of all UE-VTE cases; 0.08% of total sample). Multivariable logistic regression showed that coexisting heart failure and estrogen use were associated with increased risk of UE-VTE.

CONCLUSIONS

Although uncommon, the development of UE-VTE after open reduction and internal fixation for distal radius fractures is a concerning complication. Coexisting heart failure and estrogen use are associated with increased risk of UE-VTE.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.

Derivation and Validation of a Risk Factor Model to Identify Medical Inpatients at Risk for Venous Thromboembolism

BACKGROUND

Venous thromboembolism (VTE) prophylaxis is recommended for hospitalized medical patients at high risk for VTE. Multiple risk assessment models exist, but few have been compared in large data sets.

METHODS

We constructed a derivation cohort using 6 years of data from 13 hospitals to identify risk factors associated with developing VTE within 14 days of admission. VTE was identified using a complex algorithm combining administrative codes and clinical data. We developed a multivariable prediction model and applied it to 2 validation cohorts: a temporal cohort, including two additional years and a cross-validation, in which we refit the model excluding one hospital at a time, and applied the refitted model to the holdout hospital. Performance was evaluated using the C-statistic.

RESULTS

The derivation cohort included 160,928 patients with a 14-day VTE rate of 0.79%. The final multivariable model contained 13 patient risk factors. The model had an optimism corrected C-statistic of 0.80 and good calibration. The temporal validation cohort included 55,301 patients, with a VTE rate of 0.74%. Based on the c-statistic, the Cleveland Clinic Model (CCM) outperformed the Padua model (0.76 vs. 0.72, p<0.01). The CCM was more sensitive (65.8% vs. 60.4%, p=0.05) and more specific (74.9% vs. 71.4%, p<.001), with higher positive (1.9% vs. 1.5%, p<.001) and negative predictive values (99.7% vs. 99.6%, p=0.01). C-statistics for the CCM at individual hospitals ranged from 0.64 to 0.76.

CONCLUSION

A new VTE risk assessment model outperformed the Padua model. After further validation it could be recommended for widespread use.

Proteinuria and venous thromboembolism in pregnancy: a population-based cohort study

Background

Pregnancy-associated venous thromboembolism (VTE) is associated with high morbidity and mortality. Identification of risk factors of VTE may lead to improved maternal and foetal outcomes. Proteinuria confers a pro-thrombotic state, however, its association with VTE in pregnancy remains unknown. We set out to assess the association of proteinuria and VTE during pregnancy.

Methods

We conducted a population-based, retrospective cohort study of all pregnant women (≥16 years of age) with a proteinuria measure within 20 weeks of conception (n = 306 244; mean age 29.8 years) from Ontario, Canada. Proteinuria was defined by any of the following: urine albumin:creatinine ratio ≥3 mg/mmol, urine protein:creatinine ratio ≥5 mg/mmol or urine dipstick proteinuria ≥1. The main outcome measure was a diagnosis of VTE up to 24-weeks post-partum.

Results

A positive proteinuria measurement occurred in 8508 (2.78%) women and was more common with a history of kidney disease, gestational or non-gestational diabetes mellitus and hypertension. VTE events occurred in 625 (0.20%) individuals, with a higher risk among women with positive proteinuria [32 events (0.38%)] compared with women without proteinuria [593 events (0.20%); inverse probability-weighted risk ratio 1.79 (95% confidence interval 1.25-2.57)]. The association was consistent using a more specific VTE definition, in the post-partum period, in high-risk subgroups (hypertension or diabetes) and when the sample was restricted to women with preserved kidney function.

Conclusions

The presence of proteinuria in the first 20 weeks of pregnancy is associated with a significantly higher risk of VTE.

Inflammatory Bowel Disease Increases the Risk of Venous Thromboembolism in Children: A Population-Based Matched Cohort Study

BACKGROUND AND AIMS

Although venous thromboembolism [VTE] is a well-known complication of inflammatory bowel disease [IBD] in adults, limited data exist on the risk in children. We report the incidence of VTE among children with and without IBD.

METHODS

We conducted a matched cohort study within a distributed network of population-based Canadian provincial health administrative databases. Children <16 years diagnosed with IBD were identified using validated algorithms from administrative data in Alberta, Manitoba, Nova Scotia, Ontario and Québec and compared to age- and sex-matched children without IBD. Hospitalizations for VTE within 5 years of IBD diagnosis were identified. Generalized linear mixed-effects models were used to pool province-specific incidence rates and incidence rate ratios [IRR] with 95% confidence intervals [CI]. Hazard ratios [HR] from Cox proportional hazards models were pooled with fixed-effects meta-analysis.

RESULTS

The 5-year incidence of VTE among 3593 children with IBD was 31.2 [95% CI 23.7-41.0] per 10 000 person-years [PY] compared to 0.8 [95% CI 0.4-1.7] per 10 000 PY among 16 289 children without IBD [unadjusted IRR 38.84, 95% CI 16.59-90.83; adjusted HR 22.91, 95% CI 11.50-45.63]. VTE was less common in Crohn's disease than ulcerative colitis [unadjusted IRR 0.47, 95% CI 0.27-0.83; adjusted HR 0.52, 95% CI 0.29-0.94]. The findings were similar for deep vein thrombosis and pulmonary embolism when comparing children with and without IBD.

CONCLUSIONS

The risk of VTE is much higher in children with IBD than controls without IBD. While the absolute risk is low, we found a higher incidence rate than previously described in the pediatric literature.Conference Presentation: An abstract based on the data included in this paper was presented at Canadian Digestive Diseases Week [Montréal, Canada] in March 2020.

PERFORM: Pulmonary embolism risk score for mortality in computed tomographic pulmonary angiography-confirmed patients

BACKGROUND

Current prognostic scores for pulmonary embolism (PE) were partly based on patients without PE confirmation via computed tomographic pulmonary angiography (CTPA), involving subjective parameters and complicated scoring methods. Therefore, we sought to develop an objective, accurate, and simple prognostic model in CTPA-confirmed patients to predict the risk of 30-day mortality.

METHODS

We retrospectively evaluated 509 patients with objectively confirmed PE by CTPA from 2010 to 2017 in the Minhang Hospital, which is affiliated to Fudan University. Patients were randomly divided into the training and validation cohorts. The primary end point was 30-day mortality. The secondary end points were the time to recovery in 30 days and mortality in 15 days. We compared the predictive performance of Pulmonary Embolism Severity Index (PESI), simplified PESI (sPESI), and the PE risk score we developed, called PERFORM.

FINDINGS

PERFORM (ranging from 0 to 12 score) is based on the patient's age, heart rate, and partial pressure of arterial oxygen. The area under the curve was 0.718 (95% confidence interval [CI], 0.627-0.809) for the training cohort and 0.906 (95% CI, 0.846-0.966) for the validation cohort. PERFORM was as good as PESI and sPESI in predicting mortality. Patients in the low-risk group (PERFORM score < 5) had a shorter time to recovery, whereas those in the high-risk group (PERFORM score ≥ 5) had a high mortality.

INTERPRETATION

PERFORM in CTPA-confirmed patients is an objective, accurate, and simple tool to predict the risk of 30-day mortality.

FUNDING

Research Project of Shanghai Municipal Commission of Health and Family Planning (201740127), Shanghai Medical Key Subject Construction Project (ZK2019B08).

Incidence of Venous Thromboembolism in Patients With Dermatologist-Diagnosed Chronic Inflammatory Skin Diseases

Importance

Several studies have linked chronic inflammatory skin diseases (CISDs) with venous thromboembolism (VTE) in a range of data sources with mixed conclusions.

Objective

To examine the incidence of VTE in patients with vs without CISD.

Design, Setting, and Participants

A cohort study using commercial insurance claims data from a nationwide US health care database from January 1, 2004, through 2019 was conducted. A total of 158 123 patients with dermatologist-recorded psoriasis, atopic dermatitis, alopecia areata, vitiligo, or hidradenitis suppurativa were included. Risk-set sampling identified patients without a CISD. Patient follow-up lasted until the first of the following occurred: VTE, death, disenrollment, or end of data stream.

Exposures

Patients with vs without CISD.

Main Outcomes and Measures

Venous thromboembolism events were identified with validated algorithms. Incidence rates were computed before and after 1:1 propensity-score matching to account for VTE risk factors. Hazard ratios were estimated to compare the incidence of VTE in the CISD vs non-CISD cohorts.

Results

A total of 158 123 patients were identified with CISD: with psoriasis (n = 96 138), atopic dermatitis (n = 30 418), alopecia areata (n = 17 889), vitiligo (n = 7735), or HS (n = 5934); 9 patients had 2 of these conditions. A total of 1 570 387 patients were without a CISD. The median follow-up time was 1.9 years (interquartile range, 0.8-4.0 years) in patients with CISD. The incidence rate (per 1000 person-years) of outpatient or inpatient VTE was 1.57 in psoriasis, 1.83 in atopic dermatitis, 0.94 in alopecia areata, 0.93 in vitiligo, 1.65 in HS and 1.53 in CISD overall, compared with 1.76 in patients without a CISD. Incidence rates increased in patients aged 50 years or older (2.3 per 1000 person-years) and decreased in those aged 18 to 49 years (0.8 per 1000 person-years). After propensity-score matching to patients without a CISD, the hazard ratio (HR) of VTE was 0.86 (95% CI, 0.75-0.99) in psoriasis, 1.19 (95% CI, 0.95-1.48) in atopic dermatitis, 0.97 (95% CI, 0.65-1.46) in alopecia areata, 0.90 (95% CI, 0.49-1.65) in vitiligo, 1.64 (95% CI, 0.82-3.27) in hidradenitis suppurativa, and 0.94 (95% CI, 0.84-1.05) in CISD overall.

Conclusions and Relevance

In this large-scale cohort study, CISDs were not associated with an increased incidence of VTE after controlling for relevant VTE risk factors in a representative dermatology patient population.

Adverse event rates associated with oral anticoagulant treatment early versus later after hospital discharge in older adults: a retrospective population-based cohort study

BACKGROUND

Oral anticoagulants are commonly used high-risk medications, but little is known about their safety in transition from hospital to home. Our objective was to measure the rates of hemorrhage and thromboembolic events among older adults receiving oral anticoagulant treatment early after hospital discharge compared to later.

METHODS

We conducted a retrospective population-based cohort study among Ontario residents aged 66 years or more who started, continued or resumed oral anticoagulant therapy at hospital discharge between September 2010 and March 2015. We calculated the rates of hemorrhage and thromboembolic events requiring hospital admission or an emergency department visit over a 1-year follow-up period, stratified by the first 30 days after discharge and the remainder of the year. We used multivariable regression models, adjusting for covariates, to estimate the effect of sex, prevalent versus incident use, and switching anticoagulants on events.

RESULTS

A total of 123 139 patients (68 408 women [55.6%]; mean age 78.2 yr) were included. About one-quarter (32 563 [26.4%]) had a Charlson Comorbidity Index score of 2 or higher. The rates of hemorrhage and thromboembolic events per 100 person-years were highest during the first 30 days after hospital discharge (25.8, 95% CI 24.8-26.8 and 19.3, 95% CI 18.4-20.2, respectively), falling to 15.7 (95% CI 15.3-16.1) and 6.9 (95% CI 6.6-7.1), respectively, during the subsequent 11 months. Multivariable analysis showed that patients whose anticoagulant was switched in hospital and men had more hemorrhages and thromboembolic events in follow-up.

INTERPRETATION

The first few weeks following hospital discharge represent a very high-risk period for adverse events related to oral anticoagulant treatment among older adults. The results support an intervention trial addressing anticoagulation management in the early postdischarge period.

Effectiveness and safety of direct oral anticoagulants in patients with cancer associated venous thromboembolism

INTRODUCTION

Real-world evidence on the effects of direct oral anticoagulants (DOACs) in patients with cancer associated venous thromboembolism (VTE) is limited. Thus, our population-based cohort study aimed to assess the effectiveness and safety of DOACs compared to the standard of care low-molecular-weight heparin (LMWH) in this vulnerable population.

MATERIALS AND METHODS

Using linked administrative healthcare databases from the province of Québec, Canada, we identified patients with incident VTE from 2012 to 2015 and a cancer diagnosis in the year before the VTE, who initiated treatment with anticoagulants within 30 days after the VTE. Using an active comparator new-user design with an as-treated exposure definition, we compared use of DOACs with use of LMWH. Cox proportional hazards models estimated adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of recurrent VTE, major bleeding, and all-cause mortality. In secondary analyses, we stratified by age and sex.

RESULTS

Overall, 4438 patients with cancer associated VTE initiated treatment with anticoagulants (513 DOACs, 2698 LMWH). During a median follow-up of 0.3 years, and compared with LMWH, DOACs were associated with a decreased risk of recurrent VTE (HR, 0.54; 95% CI, 0.36-0.82) and major bleeding (HR, 0.54; 95% CI, 0.31-0.96). We also observed a decreased risk of all-cause mortality with DOACs compared with LMWH (HR, 0.14; 95% CI, 0.09-0.22). Age and sex did not modify the associations.

CONCLUSIONS

DOACs were associated with improved effectiveness and safety compared with LMWH in patients with cancer related VTE. Unmeasured confounding probably contributed to our findings on all-cause mortality.

Outpatient Management of Patients Following Diagnosis of Acute Pulmonary Embolism

OBJECTIVE

While guidelines recommend outpatient management of patients with low-risk pulmonary embolism (PE), little is known about the disposition of patients with PE diagnosed in United States emergency departments (EDs). We sought to determine disposition practices and subsequent health care utilization in patients with acute PE in U.S. EDs.

METHODS

This was a retrospective cohort study of adult ED patients with a new diagnosis of acute PE treated at 740 U.S. acute care hospitals from July 1, 2016, through June 30, 2018. The primary outcome was the initial disposition following an ED visit for acute PE. Additional measures included hospital cost and 30-day revisit rate to the ED.

RESULTS

A total of 61,070 cases were included in the overall cohort, of which 4.1% of new cases of PE were discharged from the ED. The median hospital-specific proportion of patients discharged was 3.1% (interquartile range = 0.8%-6.8%). The median odds ratio, representing the importance of the hospital in initial disposition decisions, was 2.21 (95% confidence interval = 2.05 to 2.37), which was greater than any patient-level factor with the exception of concurrent ED diagnosis of hypoxemia/respiratory failure, shock, or hypotension. Within 30 days of discharge, 17.9% of discharged cases had an ED return visit to the ED only and 10.3% of patients were hospitalized. Of the 30-day ED return visits in patients initially managed as outpatients, 1.3% had a bleeding-associated diagnosis.

CONCLUSION

Despite guidelines promoting outpatient management, few patients are currently discharged home in the United States; however, practice varies widely across hospitals. Return visit rates were high but most did not result in hospitalization.