Development of A Clinical Prediction Rule for Risk Stratification of Recurrent Venous Thromboembolism In Patients with Cancer-Associated Venous Thromboembolism

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 475-475 ◽  
Author(s):  
Martha L Louzada ◽  
Alejandro Lazo-Langner ◽  
Vi Dao ◽  
Jerry Zhang ◽  
Michael J. Kovacs ◽  
...  
Keyword(s):  
Venous Thromboembolism ◽  
High Risk ◽  
Prediction Rule ◽  
Clinical Prediction Rule ◽  
Low Risk ◽  
Clinical Prediction ◽  
Potential Predictor ◽  
Patients With Cancer ◽  
History Of ◽  
Recurrent Vte

Abstract Abstract 475 Background: Current guidelines suggest that all cancer patients with venous thromboembolism be treated with long-term low molecular weight heparin (LMWH). However, whether treatment strategies should vary according to patient and malignancy characteristics, in particular whether patients with low risk of VTE recurrence can be identified, remains unknown. Methods: We performed a single centre retrospective cohort study conducted at the Thrombosis Unit of the Ottawa Hospital. The charts of patients with cancer and VTE followed from 2002 to 2004 and from 2007 to 2008 were reviewed to assess the feasibility of derivation of a clinical prediction rule that stratifies VTE recurrence risk in patients with cancer—associated venous thrombosis through identification and evaluation of characteristics of malignancy and other clinical characteristics. We analysed only the patients who had a recurrent VTE within the first 6 months of anticoagulation. A univariate analysis determined the strength of association between each potential predictor and VTE recurrence. All potential predictor variables (p<0.25) were evaluated in a logistic regression model. Result: Of 543 patients 55 (10.1%) presented with a VTE recurrence during the first 6 months of anticoagulation. At VTE recurrence 19 (9.5%) patients were using VKA and 36 (10.5%) patients were using LMWH. The relative risk for VTE recurrence was not significantly different between patients who used VKA or LMWH [RR= 1. 13 (95%CI, 0.743 – 1.711; p= 0.565)]. A multivariate analysis suggested that gender, primary tumour site, tumour stage and history of prior VTE were significant variables to include in the clinical prediction rule. The final model included female gender, lung cancer and prior history of VTE as increasing risk and breast cancer and stage I disease as lowering risk. Patients with a score equal or less than 0 have low risk (4.5%) for VTE recurrence and this represented 48% of our patients. Patients with a score equal or above 1 have high risk (> 19%) for VTE recurrence (Tables 1 and 2). Conclusion: We were able to derive a simple and easy scoring system that stratifies patients with cancer-associated thrombosis into low or high risk of recurrent VTE. Future prospective validation of the model is warranted and may be very relevant to better tailor anticoagulation treatment in this heterogeneous population. Disclosure: No relevant conflicts of interest to declare.

Predicting Venous Thromboembolism Recurrence Risk in Patients with Cancer: A Validation Study

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 394-394
Author(s):  
Martha L Louzada ◽  
Gauruv Bose ◽  
Andrew Cheung ◽  
Benjamin H Chin-Yee ◽  
Simon Wells ◽  
...  
Keyword(s):  
High Risk ◽  
Low Molecular Weight Heparin ◽  
Treatment Strategies ◽  
Prediction Rule ◽  
Clinical Prediction Rule ◽  
Recurrence Risk ◽  
Low Molecular Weight ◽  
Clinical Prediction ◽  
Unusual Site ◽  
Patients With Cancer

Abstract Abstract 394 Background: Long-term low molecular weight heparin (LMWH) is the current standard for treatment of venous thromboembolism (VTE) in cancer patients. Whether treatment strategies should vary according to individual risk of VTE recurrence remains unknown. We have derived a clinical prediction rule that stratifies VTE recurrence risk in patients with cancer-associated VTE. The derivation model includes 4 independent predictors (sex, primary tumor site, stage and prior VTE). The score sum ranges between −3 and +3 points. Patients with a score ≤ 0 had low risk (≤4.5%) for recurrence and patients with a score above 1 had a high risk (≥ 19%) for VTE recurrence. Subsequently, we applied and validated the rule in an independent set of 819 patients from 2 randomized controlled trials comparing LMWH to warfarin for VTE treatment in cancer patients. In the current study we aim to externally validate our clinical prediction rule with an independent population of patients with cancer-associated VTE followed at the Thrombosis clinics of two tertiary Canadian centres. Methods: We conducted a retrospective cohort study of patients with cancer and VTE diagnosed and/or followed at the Thrombosis Clinic of the Victoria Hospital (London, Canada) from January 2006 to December 2010; and the Thrombosis Unit of the Ottawa Hospital (Ottawa, Canada) from January 2009 to December 2011. We included data from adult patients with active malignancy and objectively diagnosed acute pulmonary embolism (PE) or deep venous thrombosis (DVT) of the lower extremity (above knee), upper extremity and neck veins, or unusual site thrombosis. The primary outcome measure was VTE recurrence during the first six months of anticoagulation. Results: 353 patients fulfilled our inclusion criteria and were included in the study. There were 149 males, and the overall population had a median age of 64 years (range: 18 – 95). One hundred and twenty-three patients had lower extremity DVT, 93 had PE and 57 had both. The remaining 80 patients had either upper extremity/neck DVT (n = 55) or unusual site thrombosis (n = 25). 77 patients had a prior history of VTE. The most common primary tumour site was gastrointestinal, followed by the lung. Of the 304 patients with solid tumours, 230 (75.7%%) had TNM greater than I. Two hundred and ninety-three (83.0%) patients were treated with longterm low molecular weight heparin (LMWH) only and 60 (17.0%) with warfarin (VKA). VTE recurrence occurred in 44 of 353 patients (12.4%). When we evaluated VTE recurrence risk per site, there was no significant difference: London 13 of 90 and Ottawa 31 of 263 [RR=1.23 (95%CI= 0.671 – 2.237; p=0. 507)]. In addition, there was no significant benefit with the use of LMWH (37 of 293) over VKA (7 of 60) in the risk of recurrence [RR=0.92 (95%CI= 0.433 – 1.973; p= 0.8379)]. When we applied our clinical prediction rule (Table 1) in the entire study population, recurrent VTE occurred in 12 of 204 (5.8%) patients stratified as low risk probability and in 32 of 149 (21.4%) patients stratified as high risk probability (Table 2). Conclusions: Our prediction rule has been adequately validated to now be used in prospective trials of treatment. Future trials evaluating novel treatment strategies for high risk patients are warranted. Disclosures: No relevant conflicts of interest to declare.

“Low-Risk” Prediction Rule for Pediatric Oncology Patients Presenting With Fever and Neutropenia

2000 ◽  
Vol 18 (5) ◽  
pp. 1012-1012 ◽  
Author(s):  
Robert J. Klaassen ◽  
T. Robin Goodman ◽  
Ba Pham ◽  
John J. Doyle
Keyword(s):  
High Risk ◽  
Pediatric Oncology ◽  
Risk Group ◽  
Prediction Rule ◽  
Clinical Prediction Rule ◽  
High Risk Group ◽  
Low Risk ◽  
Monocyte Count ◽  
Clinical Prediction ◽  
Time Of Presentation

PURPOSE: To prospectively derive and validate a clinical prediction rule to allow a more tailored approach to the management of pediatric oncology outpatients presenting with fever and neutropenia. PATIENTS AND METHODS: The clinical prediction rule was derived over a 1-year period and then validated over the following 8 months in a new set of fever and neutropenia episodes. Patients were excluded if they presented with comorbidity or an abnormal chest x-ray (CXR). RESULTS: Significant bacterial infection (SBI; defined as any blood or urine culture positive for bacteria, interstitial or lobar consolidation on CXR, or unexpected death from infection) was documented in 43 of the 227 episodes. Multivariate analysis found four significant factors: bone marrow disease, general appearance unwell on initial examination, monocyte count less than 0.1 × 109/L, and peak oral or oral equivalent temperature greater than 39°C. Only the monocyte count contributed to determining a low-risk group, excluding SBI with 84% sensitivity (95% confidence interval [CI], 61% to 100%), 42% specificity (95% CI, 38% to 46%), and a negative predictive value of 92% (95% CI, 76% to 100%). If the monocyte count was ≥ 0.1 × 109/L at the time of presentation (low risk), the incidences of SBI and bacteremia were 8% and 5%, respectively, versus 25% and 17% in the high-risk group. When validated in a new population of 136 episodes of fever and neutropenia, the incidences of SBI and bacteremia in the low-risk group were 12% and 5%, respectively, and 25% and 19% in the high-risk group. CONCLUSION: Pediatric oncology outpatients with fever and neutropenia who present with an initial monocyte count of ≥ 0.1 × 109/L and do not have comorbidity or an abnormal CXR at the time of presentation are at lower risk for SBI and can be considered for less aggressive initial therapy.

Validation of A Clinical Prediction Rule for Risk Stratification of Recurrent Venous Thromboembolism In Patients with Cancer-Associated Venous Thromboembolism

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 4209-4209
Author(s):  
Martha L Louzada ◽  
Marc Carrier ◽  
Alejandro Lazo-Langner ◽  
Vi Dao ◽  
Jerry Zhang ◽  
...  
Keyword(s):  
Venous Thromboembolism ◽  
High Risk ◽  
Prediction Rule ◽  
Recurrence Risk ◽  
Low Risk ◽  
Tnm Stage ◽  
Stage I ◽  
Risk Of Recurrence ◽  
Patients With Cancer ◽  
Recurrent Venous Thromboembolism

Abstract Abstract 4209 Background: The risk of recurrent venous thromboembolism (VTE) in patients with cancer-associated VTE, remains high even with the use of low molecular weight heparin (LMWH). However, due to the heterogeneity of the disease it is probable that recurrence risk varies widely. We have developed a prediction rule to classify risk of recurrence in the first 6 months of treatment: + 1 is scored for each of female gender, lung cancer and prior VTE and – 1 is scored for breast cancer and – 2 for TNM stage 1 disease. With a score of ≤ 0, 4.5% of patients recur (this represented 48% of the patient populations), and > 0, 19.7% recur. The rule was derived in a retrospective cohort study of patients followed at the Thrombosis unit of the Ottawa hospital and requires validation. Methods: We applied our rule in a new set of 819 consecutive patients with cancer-associated VTE from 2 multicentre randomized controlled trials comparing LMWH with vitamin K antagonists (VKA) (ClotCant group). In these studies the stage of disease was not separated by exact TNM classification, rather patients were classified as stage I, II (no metastasis) versus III, IV (metastasis). As such, we redid our derivation model with stage I and II grouped together, which gave this variable a score of – 1. This resulted in a prediction rule which gave a recurrence risk that no longer clearly dichotomized risk; rather gave a low, intermediate, and high risk groups. As in our derivation study, we evaluated patients' risk of recurrence regardless of type of anticoagulant use (VKA or LMWH). Results: Of 819 patients, 86 (10.5%) presented with a VTE recurrence during the anticoagulation period. When we applied our derivation rule in this population, we were able to demonstrate a significant difference in VTE recurrence risk dependent on gender, primary tumour site, stage and history of prior VTE. Patients with a score < 0 have low risk (5.1%) for VTE recurrence and this represented 19% of the patient population; patients with a score of 0 had a intermediate risk (9.8%) and this represented 42% of patients; a score ≥ 1 was high risk (13.9%), occurring in 38% of the population. Dichotomizing the results gave a recurrence risk of 8% in patients with a score ≤ 0 and a 15.2% recurrence risk with a score > 0. Conclusion: the validation dataset suggests reproducibility of our model. The dichotomized score is less discriminatory than our original model suggesting an advantage to classifying patients tumour stage as TNM stage I versus stage II, III and IV. Unfortunately, we could not test this hypothesis with the ClotCant dataset. Our model appears to differentiate risk for recurrence and should be utilized in treatment trials: attempting novel treatment strategies in high risk patients since LMWH alone does not seem to be enough; and using the less costly typical “LMWH followed by oral anticoagulants” in the low risk population to evaluate whether VKA can be as safe and effective as long term LMWH. Disclosures: Lee: Eisai: Research Funding; Sanofi Aventis: Consultancy, Honoraria; Leo Pharma: Consultancy; Pfizer: Consultancy, Honoraria; Bayer: Honoraria; Boehringer Ingelheim: Consultancy, Honoraria, Speakers Bureau.

Performance of a diagnostic algorithm based on a prediction rule, D-dimer and CT-scan for pulmonary embolism in patients with previous venous thromboembolism

2015 ◽  
Vol 113 (02) ◽  
pp. 406-413 ◽  
Author(s):  
Paul L. den Exter ◽  
Inge C. M. Mos ◽  
Menno V. Huisman ◽  
Frederikus A. Klok ◽  
Maria José Fabiá Valls ◽  
...  
Keyword(s):  
Pulmonary Embolism ◽  
Venous Thromboembolism ◽  
Random Effect ◽  
Prediction Rule ◽  
Diagnostic Algorithm ◽  
Clinical Prediction Rule ◽  
Incidence Rates ◽  
Specific Patient ◽  
History Of ◽  
D Dimer

SummaryDiagnostic management of suspected pulmonary embolism (PE) in patients with a history of venous thromboembolism (VTE) is complicateddue to persistent abnormal D-dimer levels, residual embolic obstruction and higher clinical prediction rule (CPR) scores. We aimed to evaluate the safety and efficiency of the standard diagnostic algorithm consisting of a CPR, D-dimer test and computed tomography pulmonary angiography (CTPA) in this specific patient category. We performed a systematic literature search for prospective studies evaluating a diagnostic algorithm in consecutive patients with clinically suspected PE and a history of VTE. The VTE incidence rates during three-month follow-up and the number of indicated CTPAs were pooled using random effect models. Four studies concerning 1,286 patients were included with a pooled baseline PE prevalence of 36 % (95 % confidence interval [CI] 30–42). In only 217 patients (15 %; 95 %CI 11–20) PE could be excluded without CTPA. The three-month VTE incidence rate was 0.8 % (95 %CI 0.06–2.4) in patients managed without CTPA, 1.6 % (95 %CI 0.3–4.0) in patients in whom PE was excluded by CTPA and 1.4 % (95 %CI 0.6–2.7) overall. In the pooled studies, PE was safely excluded in patients with a history of VTE based on a CPR followed by a D-dimer test and/or CTPA, although the efficiency of the algorithm is relatively low compared to patients without a history of VTE.

The Use of a Clinical Prediction Model and D-Dimer (DD) Testing in the Diagnosis of Deep Vein Thrombosis (DVT): A Systematic Review.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1052-1052
Author(s):  
Carolyn J. Owen ◽  
Steve Doucette ◽  
Philip S. Wells
Keyword(s):  
High Risk ◽  
High Probability ◽  
Prediction Rule ◽  
Clinical Prediction Rule ◽  
Clinical Prediction ◽  
Clinical Prediction Model ◽  
Prediction Rules ◽  
Clinical Probability ◽  
Probability Estimates ◽  
Low Probability

Abstract Background: The diagnosis of DVT can be made by determining pretest probability of disease and using this information in combination with DD testing and ultrasound imaging. A number of studies have evaluated the use of clinical probability but this literature has not been summarized. Purpose: To systematically review trials that evaluated DVT prevalence using clinical prediction rules either with or without DD for the diagnosis of DVT. Data Sources: English and French language studies were identified from a MEDLINE search from 1990 to March 2004 and were supplemented by a review of all relevant bibliographies. Study Selection: Prospective management studies of symptomatic outpatients with suspected DVT in which patients were followed for a minimum of 3 months were selected. Clinical prediction rules had to be employed prior to DD and diagnostic tests. Studies were excluded if patients with a history of prior DVT were enrolled or if insufficient information was presented to calculate the prevalence of DVT for each of the 3 clinical probability estimates (low, moderate and high risk). Data Extraction: Two reviewers assessed each study for inclusion/exclusion criteria and collected data on prevalence and on sensitivity, specificity and likelihood ratios of DD in each of the 3 clinical probability estimates (low, moderate and high risk). Data Synthesis: 14 management studies involving a clinical prediction model in the diagnosis of DVT in over 8000 patients were included, of which 11 utilized DD in the diagnostic algorithm. All studies employed the same clinical prediction rule. The inverse variance weighted average prevalence of DVT in the low, moderate and high probability subgroups were 4.9% (95% CI= 4.2% to 5.7%), 17.4% (95% CI= 16.2% to 18.8%), and 53.6% (95% CI= 51.1% to 56.2%), respectively. The overall weighted prevalence was 18.3% (95% CI= 17.4% to 19.2%). The sensitivity of DD for the diagnosis of DVT in the low, moderate and high probability subgroups were 90.4% (95% CI= 84.7% to 94.2%), 92.0 % (95% CI= 89.1% to 94.2%), 93.6% (95% CI= 91.2% to 94.3%); and the specificities were 69.9% (95% CI= 68.0% to 71.8%), 52.4% (95% CI= 49.8% to 55.0%), and 43.2% (95% CI= 38.8% to 47.6%), respectively. The Mantel-Haenszel pooled estimates for diagnostic odds ratios (DOR) were 17.4 (95%CI=10.4–29.1), 10.2 (95% CI=7.1–14.6), and 10.1 (95% CI=6.9–14.9) in low, moderate and high groups respectively. Conclusion: Accurate estimates of the prevalence of DVT can be achieved using the same clinical prediction rule. Using this rule, it is unlikely that low probability patients have a DVT probability of more than 5%. Specificity of the DD seems to have clinically relevant differences depending on pretest probability but the DORs (which incorporate sensitivity and specificity) are similar. The data suggest that DVT can be excluded if patients are low probability even when DDs of lower sensitivity are employed and that DD testing has lower utility in high probability patients since false positives are common.

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