Machine learning analysis of bleeding status in venous thromboembolism patients.

Background: Anticoagulation therapy is the mainstay of therapy for patients with venous thromboembolism (VTE). However, continuing or stopping anticoagulants after the first 3 to 6 months is a difficult decision that requires ascertainment of the risk of bleeding and recurrent VTE. Despite the development of several statistical models to predict bleeding, the benefit of machine learning (ML) models has not been investigated in depth. Objectives: To assess the benefits of ML algorithms in bleeding risk evaluation in VTE patients and gain insight into their baseline information. Methods: The baseline clinical, demographic, and genotype information was collected for 2542 patients with VTE who were on extended anticoagulation therapy. Six unsupervised dimensionality reduction and clustering ML algorithms were used to visualize and cluster the data for patients with major bleeding (118 patients) and nonbleeders. Eight supervised ML algorithms were trained and compared with the previously derived clinical models using a 5-fold nested cross-validation scheme. Results: The baseline dataset for bleeders and nonbleeders showed a high degree of similarity. Two novel clusters were discovered within the dataset for bleeders based on the presence of isolated pulmonary embolism or isolated deep vein thrombosis, though the difference in bleeding risks was not statistically significant (P = .32). The supervised analysis showed that the ML and clinical models have similar discrimination (c-statistics, ∼62%) and calibration performance (Brier score, ∼0.045). Conclusion: The clinical variables recorded at baseline are not distinctive enough to improve bleeding prediction beyond the performance of the existing models, and other strategies or data modalities should be considered.

Qualitative experiences, values, and decisional needs of patients with unprovoked venous thromboembolism who suffer bleeding-"This pill will keep you alive tonight".

Background: Contemporary guidelines recommend extended-duration anticoagulation among patients with a first unprovoked venous thromboembolism (VTE). Little is known about whether this recommendation aligns with patient values after a bleeding complication. Objectives: To explore the experiences, values, and decisional needs of patients with unprovoked VTE related to extended-duration treatment after an anticoagulant-associated bleed. Methods: In this descriptive, qualitative study, face to face online semistructured interviews were conducted with patients with unprovoked VTE who had experienced bleeding and continued anticoagulant treatment in one academic hospital in Canada. Data were analyzed using directed content analysis to identify themes. Themes were mapped onto the Ottawa Decisional Support Framework to identify decisional needs. Results: Between September and December 2021, 14 patients were interviewed (age 41-69 years; 9 females). Many patients were not aware of the option to stop anticoagulation and had limited understanding of the decision about treatment duration. Despite the negative quality-of-life impact of clinically relevant bleeding during VTE treatment, the majority continued anticoagulation due to emotional trauma of VTE diagnosis, a perception that bleeding would be more manageable than VTE recurrence, a desire to maintain a connection to subspecialty care or non-VTE related benefits (eg, cancer diagnosis, protection from COVID-19). Patients' decisional needs included lack of choice awareness, inadequate support for participation, lack of personalized risk stratification, and inadequate information on monitoring and managing heavy menstrual bleeding. Conclusion: Despite the impact of anticoagulant-associated bleeding on quality of life, patients preferred continuing with anticoagulation for reasons extending beyond secondary VTE prevention. Effective decision-support interventions are needed to address unmet decisional needs.

A deep-learning approach to predict bleeding risk over time in patients on extended anticoagulation therapy.

BACKGROUND: Thus far, all the clinical models developed to predict major bleeding in patients on extended anticoagulation therapy use the baseline predictors to stratify patients into different risk groups. Therefore, these models do not account for the clinical changes and events that occur after the baseline visit, which can modify risk of bleeding. However, it is difficult to develop predictive models from the routine follow-up clinical interviews, which are irregular sequences of multivariate time series data. OBJECTIVES: To demonstrate that deep learning can incorporate patient time series follow-up data to improve prediction of major bleeding. METHODS: We used the baseline and follow-up data that were collected over 8 years in a longitudinal cohort study of 2542 patients, of whom 118 had major bleeding. Four supervised neural network-based machine-learning models were trained on the baseline, follow-up, or both datasets using 70% of the data. The performance of these models was evaluated, along with modified versions of 6 previously developed clinical models, on the remaining 30% of the data. RESULTS: An ensemble of feedforward and recurrent neural networks that used the baseline and follow-up data was the best-performing model, achieving a sensitivity and a specificity of 61% and 82%, respectively, in identifying major bleeding, and it outperformed the previously developed clinical models in terms of area under the receiver operating characteristic curve (82%) and area under the precision-recall curve (14%). CONCLUSION: Time series follow-up data can improve major bleeding prediction in patients on extended anticoagulation therapy.

Antithrombotic Therapy for VTE Disease: Compendium and Review of CHEST Guidelines 2012-2021.

The CHEST Antithrombotic Therapy for Venous Thromboembolism Disease evidence-based guidelines are now updated in a more frequent, focused manner. Guidance statements from the most recent full guidelines and two subsequent updates have not been gathered into a single source. An international panel of experts with experience in prior antithrombotic therapy guideline development reviewed the 2012 CHEST antithrombotic therapy guidelines and its two subsequent updates. All guideline statements and their associated patient, intervention, comparator, and outcome questions were assembled. A modified Delphi process was used to select statements considered relevant to current clinical care. The panel further endorsed minor phrasing changes to match the standard language for guidance statements using the modified Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) format endorsed by the CHEST Guidelines Oversight Committee. The panel appended comments after statements deemed as relevant, including suggesting that statements be updated in future guidelines because of interval evidence. We include 58 guidance statements from prior versions of the antithrombotic therapy guidelines, with updated phrasing as needed to adhere to contemporary nomenclature. Statements were classified as strong or weak recommendations based on high-certainty, moderate-certainty, and low-certainty evidence using GRADE methodology. The panel suggested that five statements are no longer relevant to current practice. As CHEST continues to update guidance statements relevant to antithrombotic therapy for VTE disease, this article serves as a unified collection of currently relevant statements from the preceding three guidelines. Suggestions have been made to update specific statements in future publications.

Quality and Patient Safety Metrics: Developing a Structured Program for Improving Patient Care in the Department of Medicine at The Ottawa Hospital.

PROBLEM: Despite increasing recognition of the importance of quality and patient safety in academic medicine, challenges remain with ensuring physician participation in quality assurance and quality improvement efforts, such as lack of compensation and enabling resources. An organizational culture that includes physician leadership and a supportive infrastructure is needed to encourage physician backing of quality and patient safety initiatives. APPROACH: The authors describe the development of a robust quality and patient safety program in the Department of Medicine at The Ottawa Hospital over the past 7 years and highlight how the department changed its organizational culture by prioritizing quality and patient safety and establishing the necessary infrastructure to support this program. Program development was characterized by 4 overarching themes: incentives, administrative structure and physician leadership, training and support, and system enhancements. OUTCOMES: As a result of the program, the department broadly implemented a standardized framework for conducting quality committee meetings and morbidity and mortality rounds and reviewing patient safety incidents and patient experience across its 16 divisions. This has led to 100% departmental compliance on corporate quality assurance metrics each year (e.g., regular multidisciplinary divisional quality committee meetings), along with physician participation in formal quality improvement initiatives that align with larger corporate goals. NEXT STEPS: The authors reflect on lessons learned during the implementation of the program and the essential elements that contributed to its success. Next steps for the program include using a centralized repository of quality and patient safety data, including patient safety incident dashboards, to encourage greater divisional collaboration on quality improvement initiatives and continuous institutional learning over time. Another important avenue will be to create an academic hub for excellence in quality and a formal approach to reward and promote physicians for their quality work.

Balancing risks of recurrent venous thromboembolism and bleeding with extended anticoagulation: a decision analysis.

Background: A decision to stop or continue anticoagulation after 3 months of anticoagulation for venous thromboembolism (VTE) should be made by weighing individual risks of recurrence and bleeding. Objectives: To determine the optimal ratio of recurrence risk reduction to increase the risk of bleeding in terms of maximizing quality-adjusted life years (QALYs) gained. Methods: Using a microsimulation model, outcomes within 5 years were simulated after assigning extended treatment if absolute recurrence risk reduction outweighed absolute increase in clinically relevant bleeding risk (International Society on Thrombosis and Haemostasis definition), weighted by a certain ratio. Data were simulated based on the Bleeding Risk Study, a prospective cohort including patients after ≥3 months of anticoagulation for unprovoked VTE or provoked VTE with history of VTE. The VTE-PREDICT risk score was used to estimate 5-year risks of recurrent VTE and clinically relevant bleeding. Results: Among 10,000 individuals (mean age, 60.2 years, 36% female), the ratio of 0.90 (95% CI, 0.51-3.40; ie, bleeding is considered 0.90 the severity of recurrent VTE), with 99% of patients assigned extended anticoagulation, was considered optimal and resulted in 93 (95% CI, -23 to 203) additional QALYs compared with the least favorable ratio (5.10, 0% extended anticoagulation). At the optimal ratio, treatment based on VTE-PREDICT yielded 44 (95% CI, -69 to 157) additional QALYs versus standard of care. Conclusion: With the current evidence, the optimal ratio between relevant bleeding risk and absolute recurrence risk reduction remains uncertain. Our results confirm that clinical equipoise exists regarding the decision to stop or continue anticoagulation after initial VTE treatment, emphasizing the importance of shared decision-making.

Serial D-dimers after anticoagulant cessation in unprovoked venous thromboembolism: Data from the REVERSE cohort study.

INTRODUCTION: While several risk stratification tools have been developed to predict the risk of recurrence in patients with an unprovoked venous thromboembolism (VTE), only 1 in 4 patients are categorized as low-risk. Rather than a one-time measure, serial D-dimer assessment holds promise to enhance the prediction of VTE recurrence after oral anticoagulant (OAC) cessation. METHODS: Using the REVERSE cohort, we compared VTE recurrence among patients with normal D-dimer levels (<490 ng/mL among males under age 70, <500 ng/mL in others) at OAC cessation and 1-month follow-up, to those with an elevated D-dimer level at either timepoint. We also evaluated VTE recurrence based on absolute increase in D-dimer levels between the two timepoints (e.g., ∆D-dimer) according to quartiles. RESULTS: Among 214 patients with serial D-dimer levels measured at OAC cessation and 1-month follow-up, an elevated D-dimer level at either timepoint was associated with a numerically higher risk of recurrent VTE than patients with normal D-dimer levels at both timepoints (6.9 % vs. 4.2 % per year, hazard ratio 1.6; 95 % CI 0.9-2.7). Among women with <2 HERDOO2 criteria, a normal D-dimer level at both timepoints predicted a very low risk of recurrent VTE during follow-up (0.8 % per year, 95 % CI 0.1-2.8). Irrespective of baseline value, recurrent VTE risk was only 3 % per year (95 % CI 1.4-5.6) among patients in the lowest ∆D-dimer quartile. CONCLUSION: Serial normal D-dimer levels have the potential to identify patients at a low risk of recurrent VTE. In addition, ∆D-dimer, irrespective of its elevation above cutoff threshold, may predict recurrent VTE.

Thrombophilia gene mutations predict venous thromboembolism in ambulatory cancer patients receiving chemotherapy.

BACKGROUND: Inherited thrombophilia and cancer both independently increase the risk of venous thromboembolism (VTE). However, whether the increased VTE risk associated with inherited thrombophilia exists in cancer patients is less clear. OBJECTIVES: Our objective was to determine the influence of inherited thrombophilia on VTE and bleeding risk in moderate-to-high-risk ambulatory cancer patients receiving chemotherapy. METHODS: We conducted a post hoc analysis using blood samples from patients enrolled in the AVERT trial to determine if previously recognized thrombophilia gene mutations (prothrombin factor [F] II G20210A, FXI, fibrinogen gamma, serpin family A member 10, FV K858R, FXIII, FV Leiden [FVL], and ABO blood) were associated with VTE or bleeding during the 7-months after starting chemotherapy. Logistic regression was used to compare heterozygous and homozygous mutations (combined) to wild-type. VTE rates, bleeding rates, and risk differences for mutations stratified by prophylactic anticoagulation use were calculated. RESULTS: Of the 447 patients, there were 39 VTE and 39 bleeding events. The odds of VTE were significantly increased with FVL mutation and non-O blood type (odds ratio [OR]: 5.2; 95% CI: 1.9-14.7 and OR: 2.7; 95% CI: 1.2-6.1, respectively). The use of anticoagulation prophylaxis resulted in complete protection in FVL patients, whereas those not receiving anticoagulation had a VTE rate of 119 per 100 patient-years. Lower VTE rates were also observed in non-O blood type patients taking prophylactic anticoagulation. No other thrombophilia genes tested were significantly associated with VTE or bleeding. CONCLUSION: Our results indicate that FVL mutation and ABO blood type may be important VTE predictors in cancer patients starting chemotherapy.

Accuracy of physicians' intuitive risk estimation in the diagnostic management of pulmonary embolism: an individual patient data meta-analysis.

BACKGROUND: In patients clinically suspected of having pulmonary embolism (PE), physicians often rely on intuitive estimation ("gestalt") of PE presence. Although shown to be predictive, gestalt is criticized for its assumed variation across physicians and lack of standardization. OBJECTIVES: To assess the diagnostic accuracy of gestalt in the diagnosis of PE and gain insight into its possible variation. METHODS: We performed an individual patient data meta-analysis including patients suspected of having PE. The primary outcome was diagnostic accuracy of gestalt for the diagnosis of PE, quantified as risk ratio (RR) between gestalt and PE based on 2-stage random-effect log-binomial meta-analysis regression as well as gestalts' sensitivity and specificity. The variability of these measures was explored across different health care settings, publication period, PE prevalence, patient subgroups (sex, heart failure, chronic lung disease, and items of the Wells score other than gestalt), and age. RESULTS: We analyzed 20 770 patients suspected of having PE from 16 original studies. The prevalence of PE in patients with and without a positive gestalt was 28.8% vs 9.1%, respectively. The overall RR was 3.02 (95% CI, 2.35-3.87), and the overall sensitivity and specificity were 74% (95% CI, 68%-79%) and 61% (95% CI, 53%-68%), respectively. Although variation was observed across individual studies (I2, 90.63%), the diagnostic accuracy was consistent across all subgroups and health care settings. CONCLUSION: A positive gestalt was associated with a 3-fold increased risk of PE in suspected patients. Although variation was observed across studies, the RR of gestalt was similar across prespecified subgroups and health care settings, exemplifying its diagnostic value for all patients suspected of having PE.

Recurrent venous thromboembolism and bleeding with extended anticoagulation: the VTE-PREDICT risk score.

AIMS: Deciding to stop or continue anticoagulation for venous thromboembolism (VTE) after initial treatment is challenging, as individual risks of recurrence and bleeding are heterogeneous. The present study aimed to develop and externally validate models for predicting 5-year risks of recurrence and bleeding in patients with VTE without cancer who completed at least 3 months of initial treatment, which can be used to estimate individual absolute benefits and harms of extended anticoagulation. METHODS AND RESULTS: Competing risk-adjusted models were derived to predict recurrent VTE and clinically relevant bleeding (non-major and major) using 14 readily available patient characteristics. The models were derived from combined individual patient data from the Bleeding Risk Study, Hokusai-VTE, PREFER-VTE, RE-MEDY, and RE-SONATE (n = 15,141, 220 recurrences, 189 bleeding events). External validity was assessed in the Danish VTE cohort, EINSTEIN-CHOICE, GARFIELD-VTE, MEGA, and Tromsø studies (n = 59 257, 2283 recurrences, 3335 bleeding events). Absolute treatment effects were estimated by combining the models with hazard ratios from trials and meta-analyses. External validation in different settings showed agreement between predicted and observed risks up to 5 years, with C-statistics ranging from 0.48-0.71 (recurrence) and 0.61-0.68 (bleeding). In the Danish VTE cohort, 5-year risks ranged from 4% to 19% for recurrent VTE and 1% -19% for bleeding. CONCLUSION: The VTE-PREDICT risk score can be applied to estimate the effect of extended anticoagulant treatment for individual patients with VTE and to support shared decision-making.

The risk of major bleeding in patients with factor V Leiden or prothrombin G20210A gene mutation while on extended anticoagulant treatment for venous thromboembolism.

BACKGROUND: Thrombophilia predisposes to venous thromboembolism (VTE) because of acquired or hereditary factors. Among them, it has been suggested that gene mutations of the factor V Leiden (FVL) or prothrombin G20210A mutation (PGM) might reduce the risk of bleeding, but little data exist for patients treated using anticoagulants. OBJECTIVES: To assess whether thrombophilia is protective against bleeding. METHODS: This multicentre, multinational, prospective cohort study evaluated adults receiving long-term anticoagulants after a VTE event. We analyzed the incidence of major bleeding as the primary outcome, according to the genotype for FVL and PGM (wild-type and heterozygous/homozygous carriers). RESULTS: Of 2260 patients with genotype testing, during a median follow-up of 3 years, 106 patients experienced a major bleeding event (17 intracranial and 7 fatal). Among 439 carriers of FVL, 19 experienced major bleeding and there were no differences between any mutation vs wild-type (hazard ratio [HR], 0.89 [0.53-1.49]; p = .66). The comparison of major bleeding events between the 158 patients with any-PGM mutation (heterozygous or homozygous) vs wild-type also showed a nonstatistically significant difference with HR of 0.53 (0.19-1.43), p = .21. However, multivariate analysis demonstrated that major bleeds or clinically relevant nonmajor bleeding were statistically less likely for patients with either FVL and/or PGM compared with patients with both wild-type factor V and prothrombin genes (HR, 0.73; 95% CI = 0.55-0.97; p = .03). CONCLUSION: This study demonstrates that thrombophilia, defined as the presence of either FVL or the prothrombin G20210A mutation, is related with a lower rate of major/clinically relevant nonmajor bleeding while on anticoagulants in the extended treatment for VTE.

Redefining clinical venous thromboembolism phenotypes: a novel approach using latent class analysis.

BACKGROUND: Patients with venous thromboembolism (VTE) are commonly classified by the presence or absence of provoking factors at the time of VTE to guide treatment decisions. This approach may not capture the heterogeneity of the disease and its prognosis. OBJECTIVES: To evaluate clinically important novel phenotypic clusters among patients with VTE without cancer and to explore their association with anticoagulant treatment and clinical outcomes. METHODS: Latent class analysis was performed with 18 baseline clinical variables in 3062 adult patients with VTE without active cancer participating in PREFER in VTE, a noninterventional disease registry. The derived latent classes were externally validated in a post hoc analysis of Hokusai-VTE (n = 6593), a randomized trial comparing edoxaban with warfarin. The associations between cluster membership and anticoagulant treatment, recurrent VTE, bleeding, and mortality after initial treatment were studied. RESULTS: The following 5 clusters were identified: young men cluster (n = 1126, 37%), young women cluster (n = 215, 7%), older people cluster (n = 1106, 36%), comorbidity cluster (n = 447, 15%), and history of venous thromboembolism cluster (n = 168, 5%). Patient characteristics varied by age, sex, medical history, and treatment patterns. Consistent clusters were evident on external validation. In Cox proportional hazard models, recurrence risk was lower in the young women cluster (hazard ratio [HR], 0.27; 95% CI, 0.12-0.61) compared with the comorbidity cluster, after adjusting for extended anticoagulation. The risk of bleeding was lower in young men, young women, and older people clusters (HR, 0.50; 95% CI, 0.38-0.66; HR, 0.23; 95% CI, 0.11-0.46; and HR, 0.55; 95% CI 0.41-0.73, respectively). CONCLUSION: The heterogeneity of VTE cases extends beyond the distinction between provoked and unprovoked VTE.

Predicting major bleeding during extended anticoagulation for unprovoked or weakly provoked venous thromboembolism.

No clinical prediction model has been specifically developed or validated to identify patients with unprovoked venous thromboembolism (VTE) who are at high risk of major bleeding during extended anticoagulation. In a prospective multinational cohort study of patients with unprovoked VTE receiving extended anticoagulation after completing ≥3 months of initial treatment, we derived a new clinical prediction model using a multivariable Cox regression model based on 22 prespecified candidate predictors for the primary outcome of major bleeding. This model was then compared with modified versions of 5 existing clinical scores. A total of 118 major bleeding events occurred in 2516 patients (annual risk, 1.7%; 95% confidence interval [CI], 1.4-2.1). The incidences of major bleeding events per 100 person-years in high-risk and non-high-risk patients, respectively, were 3.9 (95% CI, 3.0-5.1) and 1.1 (0.8-1.4) using the newly derived creatinine, hemoglobin, age, and use of antiplatelet agent (CHAP) model; 3.3 (2.6-4.1) and 1.0 (0.7-1.3) using modified ACCP score, 5.3 (0.6-19.2) and 1.7 (1.4-2.0) using modified RIETE score, 3.1 (2.3-3.9) and 1.1 (0.9-1.5) using modified VTE-BLEED score, 5.2 (3.3-7.8) and 1.5 (1.2-1.8) using modified HAS-BLED score, and 4.8 (1.3-12.4) and 1.7 (1.4-2.0) using modified outpatient bleeding index score. Modified versions of the ACCP, VTE-BLEED, and HAS-BLED scores help identify patients with unprovoked VTE who are at high risk of major bleeding and should be considered for discontinuation of anticoagulation after 3 to 6 months of initial treatment. The CHAP model may further improve estimation of bleeding risk by using continuous predictor variables, but external validation is required before its implementation in clinical practice.

The impact of Stress Management and Resailience Training (SMART) on academic physicians during the implementation of a new Health Information System: An exploratory randomized controlled trial.

OBJECTIVE: The Stress Management and Resilience Training (SMART) program is an evidence-based intervention designed to build resilience in physicians in clinical practice. The objective of the current study was to assess the impact of the SMART program on academic physicians' levels of resilience, subjective happiness, stress, and anxiety, and specifically during the implementation of a new hospital-wide Health Information System (HIS). METHODS: A total of 40 physicians in a tertiary care academic hospital were randomized (allocation ratio 1:1) to either the SMART intervention or the control condition. The SMART intervention consisted of one mandatory two-hour in-person workshop and an optional 24-week online program, designed to support the materials delivered in the workshop. Outcome measures were assessed using validated scales administered online at baseline and at 3-months and 6-months follow-up. RESULTS: After adjusting for baseline levels of each outcome, no statistically significant intervention effect was observed for resilience, subjective happiness, stress or anxiety at 3-months or 6-months follow-up. However, physicians in the intervention group demonstrated improvements in resilience, stress and anxiety at follow-up that were within the range of clinically relevant differences. CONCLUSIONS: The findings of this exploratory study provide modest support that the SMART intervention may be beneficial for proactively addressing physician wellness during the implementation of a new HIS and that larger randomized trials are warranted. TRIAL REGISTRATION: NCT04384861.

Evaluation of definitions for oral anticoagulant-associated major bleeding: A population-based cohort study.

INTRODUCTION: Major bleeding is the most serious complication of oral anticoagulants (OACs). While consensus criteria to define major bleeding have been established by the International Society for Thrombosis and Haemostasis (ISTH), Bleeding Academic Research Consortium (BARC) and Thrombolysis in Myocardial Infarction (TIMI), significant variability exists across these definitions. We sought to evaluate the agreement of cases identified by the three definitions and to assess their effect on mortality and OAC resumption. METHODS: We used a dataset of individuals ≥66 years in Ontario, Canada presenting with OAC-related bleeding from 2010 to 2015. For case agreement, we calculated Cohen's κ between the three major bleeding definitions. We used multivariate regression to determine differences in mortality and OAC resumption among ISTH, BARC and TIMI-defined major bleeds. RESULTS: Among 2002 cases of OAC-related bleeding, agreement in case identification between ISTH and BARC was substantial (Cohen's κ = 0.69); however, agreement between TIMI and other definitions were poor. Using 30-day mortality of clinically relevant non-major bleeds as comparator, ISTH-, BARC- and TIMI-defined major bleeds conferred 3.3-, 3.2- and 5.9-fold increased risk. Among survivors, 50% with ISTH- and BARC-defined major bleeds resumed OACs at 180 days, compared to 31% of TIMI-associated cases. CONCLUSION: Major bleeds identified by ISTH and BARC criteria showed good agreement and similar prognostic utility, whereas TIMI criteria identified patients at greater clinical risk. Our results highlight the need to revise major bleeding definitions based on criteria that are independently predictive of clinically relevant morbidity and mortality to more effectively reflect the risk associated with major bleeding and appropriately influence anticoagulant therapy decisions.

Safety and efficacy of apixaban thromboprophylaxis in ambulatory cancer patients according to renal function: A subgroup analysis of the AVERT trial.

BACKGROUND: Apixaban was effective in preventing venous thromboembolism (VTE) in ambulatory cancer patients with Khorana score ≥2 initiating chemotherapy, but with an increased risk of bleeding. Patients with cancer have a higher risk of renal dysfunction, which may be associated with increased risks of thrombotic or bleeding complications. We sought to assess the efficacy and safety of apixaban thromboprophylaxis according to renal function in the AVERT trial. METHODS: AVERT trial was a randomized, double-blinded, placebo-controlled trial evaluating apixaban as primary thromboprophylaxis for ambulatory cancer patients. The primary efficacy outcome was objectively confirmed VTE within 180 days of randomization. The primary safety outcome was major bleeding events. RESULTS: Among 574 patients randomized, 66 (11.5%) patients had CrCl <60 mL/min and 508 (88.5%) had CrCl ≥60 mL/min. Patients with CrCl <60 mL/min were older, more likely to be female, had lower weight/body mass index, and poorer ECOG performance status. In patients with CrCl <60 mL/min, there were one VTE and one major bleeding event, with no differences in outcomes between apixaban and placebo. In patients with CrCl ≥60 mL/min, apixaban was associated with a significantly lower rate of VTE and overall mortality compared to placebo without an increased risk of bleeding events. The risk of VTE was significantly higher in patients with CrCl ≥60 mL/min. CONCLUSIONS: In the AVERT trial, patients with CrCl <60 mL/min did not have higher risk of thrombotic or bleeding complications compared to those with CrCl ≥60 mL/min. (Funded by the CIHR and Bristol-Myers Squibb-Pfizer Alliance; NCT02048865).

Ruling out pulmonary embolism across different healthcare settings: A systematic review and individual patient data meta-analysis.

BACKGROUND: The challenging clinical dilemma of detecting pulmonary embolism (PE) in suspected patients is encountered in a variety of healthcare settings. We hypothesized that the optimal diagnostic approach to detect these patients in terms of safety and efficiency depends on underlying PE prevalence, case mix, and physician experience, overall reflected by the type of setting where patients are initially assessed. The objective of this study was to assess the capability of ruling out PE by available diagnostic strategies across all possible settings. METHODS AND FINDINGS: We performed a literature search (MEDLINE) followed by an individual patient data (IPD) meta-analysis (MA; 23 studies), including patients from self-referral emergency care (n = 12,612), primary healthcare clinics (n = 3,174), referred secondary care (n = 17,052), and hospitalized or nursing home patients (n = 2,410). Multilevel logistic regression was performed to evaluate diagnostic performance of the Wells and revised Geneva rules, both using fixed and adapted D-dimer thresholds to age or pretest probability (PTP), for the YEARS algorithm and for the Pulmonary Embolism Rule-out Criteria (PERC). All strategies were tested separately in each healthcare setting. Following studies done in this field, the primary diagnostic metrices estimated from the models were the "failure rate" of each strategy-i.e., the proportion of missed PE among patients categorized as "PE excluded" and "efficiency"-defined as the proportion of patients categorized as "PE excluded" among all patients. In self-referral emergency care, the PERC algorithm excludes PE in 21% of suspected patients at a failure rate of 1.12% (95% confidence interval [CI] 0.74 to 1.70), whereas this increases to 6.01% (4.09 to 8.75) in referred patients to secondary care at an efficiency of 10%. In patients from primary healthcare and those referred to secondary care, strategies adjusting D-dimer to PTP are the most efficient (range: 43% to 62%) at a failure rate ranging between 0.25% and 3.06%, with higher failure rates observed in patients referred to secondary care. For this latter setting, strategies adjusting D-dimer to age are associated with a lower failure rate ranging between 0.65% and 0.81%, yet are also less efficient (range: 33% and 35%). For all strategies, failure rates are highest in hospitalized or nursing home patients, ranging between 1.68% and 5.13%, at an efficiency ranging between 15% and 30%. The main limitation of the primary analyses was that the diagnostic performance of each strategy was compared in different sets of studies since the availability of items used in each diagnostic strategy differed across included studies; however, sensitivity analyses suggested that the findings were robust. CONCLUSIONS: The capability of safely and efficiently ruling out PE of available diagnostic strategies differs for different healthcare settings. The findings of this IPD MA help in determining the optimum diagnostic strategies for ruling out PE per healthcare setting, balancing the trade-off between failure rate and efficiency of each strategy.

VTE Prophylaxis in Critically Ill Adults: A Systematic Review and Network Meta-analysis.

BACKGROUND: Critically ill adults are at increased risk of VTE, including DVT, and pulmonary embolism. Various agents exist for venous thromboprophylaxis in this population. RESEARCH QUESTION: What is the comparative efficacy and safety of prophylaxis agents for prevention of VTE in critically ill adults? STUDY DESIGN AND METHODS: Systematic review and network meta-analysis of randomized clinical trials (RCTs) evaluating efficacy of thromboprophylaxis agents among critically ill patients. We searched six databases (including PubMed, EMBASE, and Medline) from inception through January 2021 for RCTs of patients in the ICU receiving pharmacologic, mechanical, or combination therapy (pharmacologic agents and mechanical devices) for thromboprophylaxis. Two reviewers performed screening, full-text review, and extraction. We used the Grading of Recommendations Assessment, Development, and Evaluation to rate certainty of effect estimates. RESULTS: We included 13 RCTs (9,619 patients). Compared with control treatment (a composite of no prophylaxis, placebo, or compression stockings only), low-molecular-weight heparin (LMWH) reduced the incidence of DVT (OR, 0.59 [95% credible interval [CrI], 0.33-0.90]; high certainty) and unfractionated heparin (UFH) may reduce the incidence of DVT (OR, 0.82 [95% CrI, 0.47-1.37]; low certainty). LMWH probably reduces DVT compared with UFH (OR, 0.72 [95% CrI, 0.46-0.98]; moderate certainty). Compressive devices may reduce risk of DVT compared with control treatments; however, this is based on low-certainty evidence (OR, 0.85 [95% CrI, 0.50-1.50]). Combination therapy showed unclear effect on DVT compared with either therapy alone (very low certainty). INTERPRETATION: Among critically ill adults, compared with control treatment, LMWH reduces incidence of DVT, whereas UFH and mechanical compressive devices may reduce the risk of DVT. LMWH is probably more effective than UFH in reducing incidence of DVT and should be considered the primary pharmacologic agent for thromboprophylaxis. The efficacy and safety of combination pharmacologic therapy and mechanical compressive devices were unclear. TRIAL REGISTRY: Open Science Framework; URL: https://osf.io/694aj.

A cross-sectional study of the interrelationship between burnout, empathy and resilience in academic physicians.

Burnout is a growing concern, with significant negative consequences for physicians and patient care. Burnout is negatively associated with physician empathy, while resilience may be a protective factor against the development of burnout but few studies have examined all three constructs in the same cohort. Understanding the associations between these constructs could aid in the development of interventions for physicians experiencing burnout and improve the delivery of compassionate care. We conducted a cross-sectional survey to determine levels of burnout, empathy and resilience in a sample of academic physicians and investigate the relationships between these variables. Validated scales were administered online to measure burnout (Maslach Burnout Inventory - Human Services Survey, MBI-HSS), empathy (Jefferson Scale of Empathy - Physicians/Health Professions Version, JSE) and resilience (Connor-Davidson Resilience Scale, CD-RISC). Descriptive statistics, correlation coefficients, and group comparisons were examined. Eighty-three physicians completed the JSE and CD-RISC, while a subset of 49 physicians also completed the MBI-HSS. Response rates were 31.9% and 18.8%, respectively. High burnout was reported by 49% of the sample. Physicians with high burnout reported lower levels of resilience than those who were not burnt-out. No differences in levels of empathy were observed between these two groups. Older physicians (>45 years) reported higher resilience scores than younger physicians. Resilience and empathy were significantly positively correlated. The reported rate of physician burnout in this sample of academic physicians is concerning, with burnout associated with lower levels of resilience. Further research is required to explore the relationship between physician age and resilience, the impact of resilience-building interventions on burnout and empathy in physicians, and how modifying these variables influences the delivery of compassionate care for patients.

Efficacy of primary prevention of venous thromboembolism among subgroups of cancer patients undergoing chemotherapy: A post- hoc analysis of the AVERT trial.

BACKGROUND: Apixaban has been shown to significantly decrease the rate of VTE among intermediate-to-high risk patients starting chemotherapy compared to placebo. This investigation sought to determine the impact of apixaban among different subgroups of patients with cancer. METHODS: This is a pre-planned post-hoc analysis of the AVERT randomized controlled trial which compared apixaban to placebo for the primary prevention of VTE in ambulatory patients initiating chemotherapy. Subgroup analyses were performed based on different baseline characteristics. The primary efficacy outcome was objectively documented major VTE. Hazard ratios (HR) with 95% confidence intervals (CI) were calculated using the Cox proportional hazards model to compare the treatment effect accounting for clustering at study center level. RESULTS: During the study period, major VTE events occurred in 4.2% and 10.2% of the apixaban and placebo groups, respectively (HR 0.41; 95%CI, 0.26-0.65). Characteristics associated with decreased risk of major VTE among patients on apixaban included: male sex (HR 0.25, 95%CI 0.12-0.48); weight > 90Kg (HR 0.18, 95%CI, 0.06-0.52); no prior history of VTE (HR 0.41, 95%CI 0.26-0.64); solid cancers (HR 0.30; 95%CI, 0.19-0.47); metastatic disease (HR 0.45; 95%CI, 0.26-0.78); and concurrent use of antiplatelet therapy (HR 0.18, 95%CI 0.10-0.33). CONCLUSIONS: In the AVERT trial, while apixaban thromboprophylaxis reduced the risk of major VTE in most patients, patients with weight > 90 kg, solid cancers, or concurrent antiplatelet therapy experienced the greatest benefits.