Estimation Of Clinical Probability Research Articles

Genetic testing for thrombophilia in case of unprovoked episode of pulmonary embolism

Venous thromboembolism (pulmonary embolism (PE) and deep vein thrombosis (DVT)) is the third among all cardiovascular syndromes in the world, second only to heart attack and stroke. Estimation of clinical probability of this condition takes into account many factors, including age. But in case of PE probability in young patient data of scales such as Geneva Score (Revised), Wells' criteria for pulmonary embolism, the PERC rule may be misleading. For this group a new influential factor emerges – thrombophilia. The aim of our work was to demonstrate the approach to identifying whom and when to test for genetic predisposition for thrombosis, based on a clinical case of young male with unprovoked episode of PE. Testing patients for thrombophilia is a good way to develop a personalised approach in case of prescribing long-term anticoagulant treatment. Moreover, patient’s awareness about congenital condition helps to increase complience which is crucial, due to the fact that in case of unprovoked pulmonary embolism another episode can occur in up to 50 % of cases during the next 5 years. In addition, further accumulation and analysis of data on the amount of genetic risk factors for thrombosis will expand our understanding of this issue and in the future will allow us to better diagnose and treat this condition.

Prediction of cerebral venous thrombosis with a new clinical score and D-dimer levels.

To investigate prediction of cerebral venous thrombosis (CVT) by clinical variables and D-dimer levels. This prospective multicenter study included consecutive patients with clinically possible CVT. On admission, patients underwent clinical examination, blood sampling for D-dimers measuring (ELISA test), and magnetic resonance/CT venography. Predictive value of clinical variables and D-dimers for CVT was calculated. A clinical score to stratify patients into groups with low, moderate, or high CVT risk was established with multivariate logistic regression. CVT was confirmed in 26.2% (94 of 359) of patients by neuroimaging. The optimal estimate of clinical probability was based on 6 variables: seizure(s) at presentation (4 points), known thrombophilia (4 points), oral contraception (2 points), duration of symptoms >6 days (2 points), worst headache ever (1 point), and focal neurologic deficit at presentation (1 point) (area under the curve [AUC] 0.889). We defined 0 to 2 points as low CVT probability (negative predictive value [NPV] 94.1%). Of the 186 (51.8%) patients who had a low probability score, 11 (5.9%) had CVT. The frequency of CVT was 28.3% (34 of 120) in patients with a moderate (3-5 points) and 92.5% (49 of 53) in patients with a high (6-12 points) probability score. All low CVT probability patients with CVT had D-dimers >500 μg/L. Predictive value of D-dimers for CVT for >675 μg/L (best cutoff) vs >500 μg/L was as follows: sensitivity 77.7%, specificity, 77%, NPV 90.7%, and accuracy 77.2% vs sensitivity 89.4%, specificity 66.4%, NPV 94.6%, and accuracy 72.4%, respectively. Adding the clinical score to D-dimers >500 μg/L resulted in the best CVT prediction score explored (at the cutoff ≥6 points: sensitivity 83%/specificity 86.8%/NPV 93.5%/accuracy 84.4%/AUC 0.937). The proposed new clinical score in combination with D-dimers may be helpful for predicting CVT as a pretest score; none of the patients with CVT showed low clinical probability for CVT and D-dimers <500 μg/L. NCT00924859.

Accuracy of Emergency Department Clinical Findings for Diagnosis of Coronavirus Disease 2019

Study objectiveWe seek to describe the medical history and clinical findings of patients attending the emergency department (ED) with suspected coronavirus disease 2019 (COVID-19) and estimate the diagnostic accuracy of patients’ characteristics for predicting COVID-19.MethodsWe prospectively enrolled all patients tested for severe acute respiratory syndrome coronavirus 2 by reverse-transcriptase polymerase chain reaction in our ED from March 9, 2020, to April 4, 2020. We abstracted medical history, physical examination findings, and the clinical probability of COVID-19 (low, moderate, and high) rated by emergency physicians, depending on their clinical judgment. We assessed diagnostic accuracy of these characteristics for COVID-19 by calculating positive and negative likelihood ratios.ResultsWe included 391 patients, of whom 225 had positive test results for severe acute respiratory syndrome coronavirus 2. Reverse-transcriptase polymerase chain reaction result was more likely to be negative when the emergency physician thought that clinical probability was low, and more likely to be positive when he or she thought that it was high. Patient-reported anosmia and the presence of bilateral B lines on lung ultrasonography had the highest positive likelihood ratio for the diagnosis of COVID-19 (7.58, 95% confidence interval [CI] 2.36 to 24.36; and 7.09, 95% CI 2.77 to 18.12, respectively). The absence of a high clinical probability determined by the emergency physician and the absence of bilateral B lines on lung ultrasonography had the lowest negative likelihood ratio for the diagnosis of COVID-19 (0.33, 95% CI 0.25 to 0.43; and 0.26, 95% CI 0.15 to 0.45, respectively).ConclusionAnosmia, emergency physician estimate of high clinical probability, and bilateral B lines on lung ultrasonography increased the likelihood of identifying COVID-19 in patients presenting to the ED.

Accuracy of Emergency Department Clinical Findings for Diagnostic of Coronavirus Disease-2019

Objective: We sought to describe the medical history and clinical findings of patients attending the ED with suspected COVID-19 and estimate the diagnostic accuracy of patients’ characteristics for predicting COVID-19. Methods: We prospectively enrolled all patients tested for SARS-CoV-2 by RT-PCR in our ED from March 9, 2020 to April 4, 2020. We abstracted medical history, physical examination findings, and the clinical probability of COVID-19 (“low”, “moderate”, “high”) rated by emergency physicians depending on their clinical judgment. We assessed diagnostic accuracy of these characteristics for COVID-19 by calculating positive and negative likelihood ratios (LR+/LR-). Results: We included 391 patients of whom 225 tested positive for SARS-CoV-2. RT-PCR was more likely to be negative when the emergency physician thought that clinical probability was low, and more likely to be positive when she or he thought that clinical probability was high. Patient-reported anosmia and the presence of bilateral B-lines on lung ultrasound had the highest LR+ for the diagnosis of COVID-19 (7.58; 95% CI 2.36–24.36 and 7.09; 95% CI 2.77–18.12 respectively). The absence of a high clinical probability determined by the emergency physician and the absence of bilateral B-lines on lung ultrasound had the lowest LR- for the diagnosis of COVID-19 (0.33; 95% CI 0.25–0.43 and 0.26; 95% CI 0.15–0.45 respectively). Conclusions: Anosmia, emergency physician estimate of high clinical probability and bilateral B-lines on lung ultrasound increased the likelihood of identifying COVID-19 in patients presenting to the ED.

Diagnosis of deep-vein thrombosis

The diagnostic approach to suspected symptomatic deep-vein thrombosis of the lower extremities is usually based on non-invasive methods, including the estimation of clinical probability, the measurement of D-dimer levels, and ultrasonography. The present review discusses the evidence available from the literature about the management of the first episode of suspected deep-vein-thrombosis.

A Retrospective Evaluation of Patients Admitted to Emergency Departments with Pulmonary Thromboembolism

2 , Bulent Sisman 3 Abstract Aim: To examine the clinical, radiological, and laboratory findings of pulmonary thromboembolism (PTE) patients who were admitted to our emergency depart - ment and to evaluate the effectiveness of clinical diagnosis scores. Materials and Methods: We retrospectively evaluated 33 PTE patients who were referred to our emergency department. Results: The mean age of the patients was 56.2±18.2 years. The female:male ratio was 1.5. The most common cause of complaints was dyspnoea (51.5%). Risk factors in the majority (39.3%) included immobilisation due to surgery. According to the Wells clinical scoring system, 29 patients (87.8%) had a high probability of PTE; however, 18 of the patients (55.5%) had high probability of PTE according to the modified Geneva score. The estimated rate ratio of high probability of PTE with the Wells score was statistically significant compared with the estimate rate ration with the modified Geneva score (p=0.017). The most common clinical findings included tachypnoea (69.6%) and tachycardia (27.3%). Fifteen (45.4%) patients had pathologic chest X-ray findings. Computed tomographic (CT) angiography most often showed PTE placement of the bilateral pulmonary main branches. While standard low-molecular-weight heparin and warfarin treatment was administered to 27 (81.8%) patients, tissue plasminogen activator (tPA) treatment was administered to 6 (18.2%) patients. Conclusion: The evaluation of clinical, laboratory and radiological findings together in PTE diagnosis is important. It is preferable to use the Wells score for the estimation of clinical probability in patients with suspected PTE. (JAEM 2015; 14: 8-11)

Comparison of empirical estimate of clinical pretest probability with the Wells score for diagnosis of deep vein thrombosis

Wells score has been validated for estimation of pretest probability in patients with suspected deep vein thrombosis (DVT). In clinical practice, many clinicians prefer to use empirical estimation rather than Wells score. However, which method is better to increase the accuracy of clinical evaluation is not well understood. Our present study compared empirical estimation of pretest probability with the Wells score to investigate the efficiency of empirical estimation in the diagnostic process of DVT. Five hundred and fifty-five patients were enrolled in this study. One hundred and fifty patients were assigned to examine the interobserver agreement for Wells score between emergency and vascular clinicians. The other 405 patients were assigned to evaluate the pretest probability of DVT on the basis of the empirical estimation and Wells score, respectively, and plasma D-dimer levels were then determined in the low-risk patients. All patients underwent venous duplex scans and had a 45-day follow up. Weighted Cohen's κ value for interobserver agreement between emergency and vascular clinicians of the Wells score was 0.836. Compared with Wells score evaluation, empirical assessment increased the sensitivity, specificity, Youden's index, positive likelihood ratio, and positive and negative predictive values, but decreased negative likelihood ratio. In addition, the appropriate D-dimer cutoff value based on Wells score was 175 μg/l and 108 patients were excluded. Empirical assessment increased the appropriate D-dimer cutoff point to 225 μg/l and 162 patients were ruled out. Our findings indicated that empirical estimation not only improves D-dimer assay efficiency for exclusion of DVT but also increases clinical judgement accuracy in the diagnosis of DVT.

Coronary artery plaques and myocardial ischaemia

To prospectively examine coronary artery plaques as predictors of myocardial ischaemia using cardiac magnetic resonance (CMR). Fifty-two patients (46 men; age 64 ± 10) with suspected coronary artery disease (CAD) referred for catheter coronary angiography (CA) underwent CMR and computed tomography coronary angiography (CTCA). All coronary segments were evaluated for morphological stenosis based on CA. Any plaque according to its composition was assessed based on CTCA. Numbers of total and calcified coronary artery plaques represented the best predictors of myocardial ischaemia (AUC = 0.87; [95%CI: 0.77-0.97] and AUC = 0.87; [95%CI: 0.77-0.96], respectively, p = 0.56) with the total plaque number significantly higher in patients with corresponding ischaemia than those without (p < 0.01, p < 0.05 adjusted for pre-test probability and stenosis). Compared with the AUC of coronary stenosis assessment by CA (AUC = 0.90; [95%CI: 0.80-1.00]), AUCs were equivalent using either the total number or the number of calcified plaques alone (p = 0.73 and p = 0.69). Multivariate logistic regression analyses demonstrated the total plaque number as an independent predictor of ischaemia (odds +20%; [95%CI: 1.096-1.368]), improving a model including clinical probability estimates of CAD (c-statistics, 0.66 to 0.89). Coronary artery plaque number according to CTCA is a significant, independent predictor of myocardial ischaemia with similar accuracy to stenosis assessment.

A New Rapid Test for the Detection of PF4:Heparin Antibodies.

AbstractAbstract 3708Heparin Induced Thrombocytopenia (HIT), the most frequent drug-induced immune-mediated type of thrombocytopenia, is an important and sometimes life-threatening complication of heparin therapy. HIT can be triggered by standard therapeutic dose heparin, low-dose (prophylactic treatment), low molecular weight heparin, unfractionated heparin and even by minute quantities given to flush intravascular catheters.HIT is a clinicopathologic syndrome cause by platelet activating antibodies that recognize complexes of platelet factor 4 and heparin (PF4-heparin). Thrombocytopenia occurring within 5 – 10 days of administration of heparin is the most common clinical effect. The most severe complication of HIT is the occurrence of both venous and arterial thrombosis. Venous thrombosis can result in limb gangrene and the need for limb amputation.The diagnosis of HIT is based on clinical abnormalities including thrombocytopenia with or without thrombosis and the detection of antibodies to the PF4-heparin complex (termed PF4 dependant antibodies). There are two major types of assays for the detection of heparin dependant antibodies: functional assays and PF4 dependant antigen immunoassays. Functional assays include the serotonin release assay (SRA) and the heparin induced platelet activation assay (HIPA). Enzyme linked immunoassays (ELISAs) are the most frequently used PF4 dependent antigen immunoassay. Functional assays are technically difficult to perform and are considered to be complex specialty assays. ELISAs while not complex are not generally available on a STAT basis. There is a need for a simpler assay which retains or improves the sensitivity and specificity of the existing immunoassays that can be available on a STAT basis.GTI Diagnostics is developing a rapid test based on the proprietary technology used in GTI's PF4 Enhanced® ELISA. The PF4 Rapid test is a single use, semi-quantitative assay contained in a cartridge. It is designed to detect anti-PF4-heparin antibodies in human serum and/or plasma with a total assay time of 15 minutes. The assay uses only 5 μL of human serum and/or plasma along with a proprietary antigen and a proprietary fluorescent secondary antibody used for detection. The assay results are read using a fluorescent reader. A method comparison study was conducted which included an evaluation of 83 serum samples obtained from patients receiving heparin of which 36 were positive and 22 were negative in the PF4 Enhanced® assay. These samples were also tested in the PF4 Rapid Test assay. In addition 25 samples from normal individuals who were not receiving heparin were tested in both assays. Analysis of the data using a 2×2 table (shown below) resulted in a sensitivity of 100%, a specificity of 93.6% and an overall agreement of 96.4% of the PF4 Rapid Test compared to the PF4 Enhanced®.PF4 Enhanced® ELISAPositiveNegativeTotalPF4 Rapid TestPositive36339Negative04444Total364783Although HIT is a true clinicopathological syndrome, its diagnosis still rests primarily on clinical grounds since laboratory tests may not be available locally or may not be available in a sufficiently timely manner. Owing to the high risk of thrombosis associated with HIT, antithrombotic therapy with alternative anticoagulants should be started immediately when serologic assays confirm clinical suspicion. Readily available results, obtained from immunoassays for rapid detection of antibodies against PF4-heparin complexes, may be combined with the pretest estimation of clinical probability in order to exclude and/or confirm the diagnosis of HIT; therefore, assisting physicians in the time-sensitive clinical management of HIT. Disclosures:Ladvienka:GTI Diagnostics, Inc: Employment. Visentin:GTI Diagnostics, Inc: Employment. Chance:GTI Diagnostics, Inc: Employment.

A Prediction Rule for Estimating the Risk of Bacteremia in Patients with Community‐Acquired Pneumonia

We endeavored to construct a simple score based entirely on epidemiological and clinical variables that would stratify patients who require hospital admission because of community-acquired pneumonia into groups with a low or high risk of developing bacteremia. Derivation and internal validation cohorts were obtained by retrospective analysis of a database that included 3116 consecutive patients with community-acquired pneumonia from 2 university hospitals. Potential predictive factors were determined by means of a multivariate logistic regression equation applied to a cohort consisting of 60% of the patients. Points were assigned to significant parameters to generate the score. It was then internally validated with the remaining 40% of patients and was externally validated using an independent multicenter cohort of 1369 patients. The overall rates of bacteremia were 12%-16% in the cohorts. The clinical probability estimate of developing bacteremia was based on 6 variables: liver disease, pleuritic pain, tachycardia, tachypnea, systolic hypotension, and absence of prior antibiotic treatment. For the score, 1 point was assigned to each predictive factor. In the derivation cohort, a cutoff score of 2 best identified the risk of bacteremia. In the validation cohorts, rates of bacteremia were <8% for patients with a score 1 (43%-49% of patients), whereas blood culture results were positive in 14%-63% of cases for patients with a score 2. This clinical score, based on readily available and objective variables, provides a useful tool to predict bacteremia. The score has been internally and externally validated and may be useful to guide diagnostic decisions for community-acquired pneumonia.

Local Applicability of Clinical and Model-Based Probability Estimates

Local Applicability of Clinical and Model-Based Probability Estimates

Review: a low clinical probability plus a normal D-dimer test result excludes a diagnosis of deep venous thrombosis

Fancher TL, White RH, Kravitz RL. Combined use of rapid D-dimer testing and estimation of clinical probability in the diagnosis of deep vein thrombosis: systematic review. BMJ 2004;329:821. [OpenUrl][1][Abstract/FREE Full...

PRIMARY URETHRAL RECONSTRUCTION: THE COST MINIMIZED APPROACH TO THE BULBOUS URETHRAL STRICTURE

Treatment for urethral stricture disease often requires a choice between readily available direct vision internal urethrotomy (DVIU) and highly efficacious but more technically complex open urethral reconstruction. Using the short segment bulbous urethral stricture as a model, we determined which strategy is less costly. The costs of DVIU and open urethral reconstruction with stricture excision and primary anastomosis for a 2 cm bulbous urethral stricture were compared using a cost minimization decision analysis model. Clinical probability estimates for the DVIU treatment arm were the risk of bleeding, urinary tract infection and the risk of stricture recurrence. Estimates for the primary urethral reconstruction strategy were the risk of wound complications, complications of exaggerated lithotomy and the risk of treatment failure. Direct third party payer costs were determined in 2002 United States dollars. The model predicted that treatment with DVIU was more costly (17,747 dollars per patient) than immediate open urethral reconstruction (16,444 dollars per patient). This yielded an incremental cost savings of $1,304 per patient, favoring urethral reconstruction. Sensitivity analysis revealed that primary treatment with urethroplasty was economically advantageous within the range of clinically relevant events. Treatment with DVIU became more favorable when the long-term risk of stricture recurrence after DVIU was less than 60%. Treatment for short segment bulbous urethral strictures with primary reconstruction is less costly than treatment with DVIU. From a fiscal standpoint urethral reconstruction should be considered over DVIU in the majority of clinical circumstances.

Review: a low clinical probability plus a normal d-dimer test result excludes a diagnosis of deep venous thrombosis

Fancher TL, White RH, Kravitz RL. Combined use of rapid d-dimer testing and estimation of clinical probability in the diagnosis of deep vein thrombosis: systematic review. BMJ 2004;329:821.[OpenUrl][1][Abstract/FREE Full Text][2]...

Management of Pulmonary Embolism in 2005

Pulmonary embolism is a common, life-threatening, yet still misdiagnosed and mistreated disease. Many aspects of the management of pulmonary embolism have changed significantly in recent years, while others have not. This review will summarize key aspects of diagnosis and treatment. Readers are referred to key texts and longer reviews for specific areas of interest. Diagnosis It is critical to understand that the vast majority of diagnostic studies have included symptomatic outpatients rather than inpatients. Inpatients have increased disease burden and more complicated illnesses. Since predictive values of diagnostic tests depend to a great degree on the preexisting probability of having a pulmonary embolism and this can be more difficult to estimate in complicated inpatients, it is understandable that the predictive values of the tests may be lower for inpatients. In outpatients, the incidence of a proven pulmonary embolism with a “negative” D-dimer accompanied by a “low clinical probability” is 1% h. 1 Two warnings pertain to using this information: This does not apply to borderline D-dimer values, and inexperienced physicians should use a clinical scoring system to arrive at their estimate of clinical probability. In outpatients, a management study of suspected pulmonary embolism has shown that no treatment is needed if the following three conditions pertain: (a) clinical suspicion is low or moderate; (b) duplex ultrasound of both proximal lower extremities (including the popliteal vein) is normal; and (c) the contrast helical CT pulmonary angiogram is truly negative (a CT that shows isolated subsegmental clot is considered indeterminate, not negative, and not positive). 2 If clinical suspicion is high, further testing is required.

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

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.

Combined use of rapid D-dimer testing and estimation of clinical probability in the diagnosis of deep vein thrombosis: systematic review

Objective To summarise the evidence supporting the use of rapid D-dimer testing combined with estimation of clinical probability to exclude the diagnosis of deep venous thrombosis among outpatients.Data sources Medline...

Non‐invasive diagnostic work‐up of patients with clinically suspected pulmonary embolism; results of a management study

Clinicians often deviate from the recommended algorithm for the diagnosis of pulmonary embolism consisting of ventilation-perfusion scintigraphy and pulmonary angiography. To assess the safety and feasibility of a diagnostic algorithm which reduces the need for lung scintigraphy and avoids the use of angiography. Consecutive patients with a clinical suspicion of pulmonary embolism were prospectively investigated according to an algorithm in which the diagnosis of pulmonary embolism was excluded after a low clinical probability estimate and a normal d-dimer test result, a normal perfusion scintigraphy result, or a non-high probability scintigraphy result in combination with normal serial ultrasonography of the legs. In these patients anticoagulant treatment was withheld and they were followed up for 3 months to record possible thromboembolic events. During the study period, 923 consecutive patients were seen, of whom 292 were excluded because of predefined criteria. Of the 631 included patients, the diagnosis was refuted on the basis of a low clinical probability estimate and a normal d-dimer test result (95 patients), normal perfusion scintigraphy (161 patients) and non-high probability lung scintigraphy followed by normal serial ultrasonography (210 patients). Of these 466 patients, venous thromboembolic complications during follow-up occurred in six (complication rate 1.3%, 95% confidence interval 0.5, 2.8). The diagnostic protocol was completed in 92% of all included patients. The diagnosis of pulmonary embolism can be safely ruled out by a non-invasive algorithm consisting of d-dimer testing combined with a clinical probability estimate, lung scintigraphy, or serial ultrasonography of the legs (in case of non-diagnostic lung scintigraphy).

Unstructured Clinician Estimate of Low Clinical Probability for Pulmonary Embolism Is Equivalent to the Canadian Score and the Charlotte Rule

Unstructured Clinician Estimate of Low Clinical Probability for Pulmonary Embolism Is Equivalent to the Canadian Score and the Charlotte Rule

Assessing clinical probability of pulmonary embolism in the emergency ward: a simple score.

To develop a simple standardized clinical score to stratify emergency ward patients with clinically suspected pulmonary embolism (PE) into groups with a high, intermediate, or low probability of PE to improve and simplify the diagnostic approach. Analysis of a database of 1090 consecutive patients admitted to the emergency ward for suspected PE in whom diagnosis of PE was ruled in or out by a standard diagnostic algorithm. Logistic regression was used to predict clinical parameters associated with PE. A total of 296 (27%) of 1090 patients were found to have PE. The optimal estimate of clinical probability was based on 8 variables: recent surgery, previous thromboembolic event, older age, hypocapnia, hypoxemia, tachycardia, band atelectasis, or elevation of a hemidiaphragm on chest x-ray film. A probability score was calculated by adding points assigned to these variables. A cutoff score of 4 best identified patients with low probability of PE. A total of 486 patients (49%) had a low clinical probability of PE (score </=4), of which 50 (10.3%) had a proven PE. The prevalence of PE was 38% in the 437 patients with an intermediate probability (score of 5-8; n = 437) and 81% in the 63 patients with a high probability (score >/=9). This clinical score, based on easily available and objective variables, provides a standardized assessment of the clinical probability of PE. Applying this score to emergency ward patients suspected of having PE could allow a more effective diagnostic process.