Simple Clinical Decision Rule Research Articles

Derivation of a clinical decision rule for a bone marrow aspirate concentrate injection in knee osteoarthritis.

Aim: To develop a simple clinical decision rule (CDR) to identify people with knee osteoarthritis who are likely or unlikely to benefit from bone marrow aspirate concentrate (BMAC) injection. Materials & methods: A total of 92 people with clinical and radiographic evidence of refractory knee osteoarthritis received a single intra-articular (IA) BMAC injection. Multiple logistic regression analysis was used to determine which combination of risk factors predicted BMAC responsiveness. A responder was defined as a person whose knee pain improved more than 15% from baseline 6months postprocedure. Results: The CDR demonstrated that those with lower pain levels, or high pain levels with previous surgery, could be predicted to benefit from a single IA BMAC injection. Conclusion: A simple CDR containing three variables predicted responsiveness to a single IA knee BMAC injection with high accuracy. Further validation of the CDR is required prior to routine use in clinical practice.

A simple clinical decision rule may help to ruleout severe bacterial infection and spare antibiotics in febrile young children.

To assess the performance of a new clinical decision rule (CDR) to identify patients at a low risk of invasive bacterial infection (IBI) among febrile children and its theoretical impact on antibiotic use. Prospective study including consecutive children <5 years of age who presented in one French paediatric emergency department with fever without source between January and December 2016. With the collected data, we constructed a CDR based on a sequential approach based on age, clinical toxic signs, urinalysis and procalcitonin level. We evaluated its diagnostic performances to identify IBI and its potential impact on antibiotic use. Among the 1061 children (IBI 11/1061, 1.0%), 693 (65.3%) were classified at low or intermediate risk of IBI, with an IBI prevalence of 0%. The sensitivity and specificity of the CDR to predict IBI were 100% and 73.9%. Negative and positive predictive value were 100% and 3.9%, respectively. Using this new CDR, the current antibiotics exposure would theoretically be reduced from 33.6% to 24.1%. The promising interest of this clinical decision rule, using simple and accessible biological and clinical tools, needs to be confirm with an external validation study, which will allow its use in clinical practice.

The Hip Center Rule Can be Used to Decide if Measured Pelvic Incidence is Accurate.

Simulation study. Pelvic incidence (PI) should be considered during surgical planning. The ideal patient position with both hip centers perfectly aligned for a lateral radiograph is rarely obtained. It has been suggested that a radiograph with axial and coronal rotation up to 20° is acceptable to obtain a measured PI within 6 degrees of the actual PI. We seek to: (1) evaluate the effect of variations in PI and patient malpositioning on measured vs true PI, and (2) determine whether the presence of one hip center within the bony acetabular rim of the contralateral hip can serve as a simple clinical decision rule on the accuracy of measured PI. Published anthropometric three-dimensional pelvic landmark coordinates were used in this study. Radiographic projections were generated using linear algebra for combinations of axial and coronal rotation from -20° to +20°. True and measured PIs were compared. Rotation to 20° cannot be uniformly accepted as decision rule. Pelvises with higher PIs are more sensitive to malpositioning with greater PI deviation with smaller amounts of rotation. Diagnostic performance of the hip center rule demonstrated a sensitivity of 25.58% and a specificity of 100.00%. Rather than assessing the quality of radiographs for PI measurement by magnitude of malpositioning, we recommend clinicians use the "hip center rule." As long as at least one hip center is contained within the bony acetabular rim of the contralateral hip, there is high confidence that measured PI will be within 6° of true PI.

A simplified decision rule to rule out deep vein thrombosis using clinical assessment and D‐dimer

BackgroundCurrent clinical decision rules to exclude deep vein thrombosis (DVT) are underused partly because of their complexity. A simplified rule that can be easily applied would be more appealing to use in clinical practice. MethodsWe used individual patient data from prospective diagnostic studies of patients suspected of DVT to develop a new clinical decision rule. The primary outcome was presence of DVT either at initial testing or during follow‐up. DVT was considered safely excluded if the upper 95% confidence interval (CI) of DVT prevalence was <2%. ResultsFour studies and 3368 patients were eligible for this analysis. Overall prevalence of DVT was 17%. In addition to D‐dimer, two variables, calf swelling and DVT as the most likely diagnosis, are included in the new rule. Based on these two variables, two clinical pretest probability (CPTP) groups were defined; low (none of the two items present) and high (at least one of the items present). DVT can be safely excluded in patients with low CPTP with a D‐dimer <500 ng/mL (prevalence = 0.1%; 95% CI, 0.0‐0.8), low CPTP with a D‐dimer between 500 ng/ml and 1000 ng/ml (prevalence = 0.3%; 95% CI, 0.0‐1.7), and D‐dimer <500 ng/ml in patients with high CPTP (prevalence = 0.3%; 95% CI, 0.0‐1.0). ConclusionsThe combination of D‐dimer and Wells items resulted in a simple clinical decision rule with 3 items. The results suggest that the rule can safely exclude DVT. Prospective validation is required.

A clinical decision rule to predict intracranial hypertension in severe traumatic brain injury.

While existing guidelines support the treatment of intracranial hypertension in severe traumatic brain injury (TBI), it is unclear when to suspect and initiate treatment for high intracranial pressure (ICP). The objective of this study was to derive a clinical decision rule that accurately predicts intracranial hypertension. Using Delphi methods, the authors identified a set of potential predictors of intracranial hypertension and a clinical decision rule a priori by consensus among a group of 43 neurosurgeons and intensivists who have extensive experience managing severe TBI without ICP monitoring. To validate these predictors, the authors used data from a Latin American trial (n = 150; BEST TRIP). To report on the performance of the rule, they calculated sensitivity, specificity, and positive and negative predictive values with 95% confidence intervals. In a secondary analysis, the rule was validated using data from a North American trial (n = 131; COBRIT). The final predictors and the clinical decision rule were approved by 97% of participants in the consensus working group. The predictors are divided into major and minor criteria. High ICP would be considered suspected in the presence of 1 major or ≥ 2 minor criteria. Major criteria are: compressed cisterns (CT classification of Marshall diffuse injury [DI] III), midline shift > 5 mm (Marshall DI IV), or nonevacuated mass lesion. Minor criteria are: Glasgow Coma Scale (GCS) motor score ≤ 4, pupillary asymmetry, abnormal pupillary reactivity, or Marshall DI II. The area under the curve for the logistic regression model that contains all the predictors was 0.86. When high ICP was defined as > 22 mm Hg, the decision rule performed with a sensitivity of 93.9% (95% CI 85.0%-98.3%), a specificity of 42.3% (95% CI 31.7%-53.6%), a positive predictive value of 55.5% (95% CI 50.7%-60.2%), and a negative predictive value of 90% (95% CI 77.1%-96.0%). The sensitivity of the clinical decision rule improved with higher ICP cutoffs up to a sensitivity of 100% when intracranial hypertension was defined as ICP > 30 mm Hg. Similar results were found in the North American cohort. A simple clinical decision rule based on a combination of clinical and imaging findings was found to be highly sensitive in distinguishing patients with severe TBI who would suffer intracranial hypertension. It could be used to identify patients who require ICP monitoring in high-resource settings or start ICP-lowering treatment in environments where resource limitations preclude invasive monitoring.Clinical trial registration no.: NCT02059941 (clinicaltrials.gov).

GD05: Careful Anticoagulation Review in Emergency Medicine (CARe-EM)

Background: The number of patients prescribed anticoagulation for stroke prevention is increasing, along with the proportion of emergency department (ED) patients who are anticoagulant users. Bleeding is the most common side effect. Inappropriate dosing, co-prescription of anti-inflammatories or aspirin, and renal impairment all increase the bleeding risk. An ED visit is an opportunity to review anticoagulant bleeding risks and intervene to prevent bleeding in patients at high risk. Objectives: To establish the 12-month incidence of bleeding in anticoagulated patients visiting the ED, to develop an ED specific anticoagulant-associated bleeding prediction score, to evaluate the ED utility of existing prediction scores. Methods: Research ethics board approval has been granted. Patients will be identified in Hamilton General and Juravinski EDs. Each patient will be followed forward in time for 12 months to document bleeding events. Population: Inclusion criteria: ED patients prescribed warfarin, rivaroxaban, dabigatran, apixaban, edoxaban or low molecular weight heparin (prevalent users). Exclusion criteria: Patients under 16 years of age. Primary outcome: The incidence of major bleeding (defined by ISTH criteria) within 12 months from the index ED visit. Secondary outcomes: Derivation of an ED prediction score to identify patients at high risk of anticoagulant-associated bleeding within 12 months. Tertiary outcomes: Evaluation of ATRIA, modified HAS-BLED and HEMORR2HAGES scores utility in predicting bleeding within 12 months. Data management: The data will be stored anonymously and securely on RedCAP. A literature search/expert discussion has identified multiple potential risk factors for bleeding. This data is collected at the time of the index ED presentation. A committee of emergency, thrombosis, gastroenterology and cardiology physicians will review each major bleeding case. Analysis: Primary analysis: a multiple logistic regression analysis to identify variables associated with major bleeding diagnosed within 12 months of the index presentation. Using the model β coefficients we will derive a simple clinical decision rule. Secondary analysis: assessing the area under the curve and optimal cut points for pre-existing bleeding prediction scores for predicting major bleeding within 12 months. Sample size calculation: With 3000 patients we expect 2700 to be anticoagulated long term, and at least 135/2700 patients will have a major bleed. This is a sufficient number for multivariate analysis to establish a simple model. We estimate 20,000 anticoagulated ED patient attendances/year. Importance: This is the first study to consider the ED visit an opportunity to prevent bleeding. We will establish a method to identify ED patients at high risk of anticoagulant-associated bleeding.

Evaluation of the new simple and objective clinical decision rule “I-DVT” in patients with clinically suspected acute deep vein thrombosis

IntroductionThe Wells rule is the recommended first step in the work-up of suspected deep vein thrombosis (DVT). However, it is often incorrectly used leading to an excessive number of diagnostic tests used in daily practice and diagnostic failures. A simpler objective risk stratification tool may improve adherence to the guidelines. We evaluated the diagnostic performance of the I-DVT score, which consists of four easy assessable variables: Immobilization, >3cm Difference in calve circumferences, prior Venous thromboembolism (VTE) and active malignant Tumor. MethodsWe performed an observational study in 617 consecutive patients with suspected DVT. All patients were managed according to the recommended algorithm starting with the Wells rule followed by D-dimer test and/or compression ultrasonography (CUS). The I-DVT score was prospectively calculated at baseline and evaluated post-hoc. ResultsThe DVT prevalence was 36%. DVT could be excluded in 13% of patients without CUS by the Wells rule and a normal D-dimer test, with a 3-month VTE incidence of 1.2% (95%CI 0.03–6.5%). Using the I-DVT score, DVT would have been excluded in 9.1% of patients without additional CUS, with a 3-month VTE incidence of 0% (95%CI 0.0–6.4%). The area under the ROC curve (AUC) was 0.70 (95%CI 0.66–0.74) and 0.65 (95%CI 0.61–0.70) for the Wells rule and I-DVT score respectively (difference 0.049, 95%CI −0.01–0.11; p=0.13). ConclusionsThe simple I-DVT score and Wells rule have comparable diagnostic accuracy. It's safety, efficiency and associated potential improvement of guideline adherence in clinical practice has to be further evaluated in a prospective management study.

A clinical decision rule identifies risk factors associated with antimicrobial-resistant urinary pathogens in the emergency department: a retrospective validation study.

Identifying patients at high risk for multidrug-resistant urinary tract infections (UTIs) is important for guiding empirical antimicrobial therapy. Clinical risk factors associated with antimicrobial-resistant urinary pathogens and the derivation of a simple clinical decision rule could help define health care-associated UTI. To derive a simple clinical decision rule to identify clinical risk factors associated with antimicrobial-resistant urinary pathogens. This was a retrospective case-control study of all emergency department (ED) patients from July 1, 2011, to July 1, 2012, who presented to the ED with UTI and a positive urine culture. Candidate risk factors were collected retrospectively from medical record review. We compared differences in patient characteristics stratified by the presence of an antimicrobial-resistant urinary pathogen. A total of 360 patients with UTI had a positive, noncontaminated urine culture during the study period. About 6.7% of patients (n = 24) had a multidrug-resistant (MDR) urinary infection. Logistic regression modeling identified 3 clinical factors associated with the identification of a MDR pathogen: male sex, chronic hemodialysis, and nursing home residence. A scoring system was created to identify patients with MDR pathogens. Test characteristics were calculated using bootstrapping for internal validation, with a sensitivity of 74.7% (95% CI = 55.1%-91.3%) and specificity of 85.1% (95% CI = 77.8%-86.2%), positive likelihood ratio of 4.3, and a negative likelihood ratio of 0.3. Clinical factors can be used to identify UTI patients at high risk of MDR urinary pathogens.

A simple clinical decision rule to rule out appendicitis in patients with nondiagnostic ultrasound results.

The objective was to identify a set of clinical features that can rule out appendicitis in patients with suspected acute appendicitis and nondiagnostic ultrasound (US) results, allowing safe discharge and next-day reevaluation without initial computed tomography (CT) or magnetic resonance imaging (MRI). Data on clinical and US evaluation, including a number of prespecified variables potentially associated with acute appendicitis, were prospectively collected in two diagnostic accuracy studies of imaging. These studies included patients with suspected appendicitis seen in the emergency department (ED). For development and validation of the clinical decision rule (CDR), only patients with inconclusive or negative US results were included. There were 199 (of 422) patients in the development cohorts and 120 (of 211) patients in the validation cohort. Logistic regression analysis was used for data from patients with inconclusive or negative US results, and profiles were created of all possible combinations of predictors retained in the multivariable model. A final diagnosis was assigned by an expert panel based on perioperative data, histopathology, and clinical follow-up of at least 3 months. The CDR selected patients after negative or inconclusive US for discharge and next-day reevaluation without initial CT or MRI if fewer than two of the following predictors were present: male sex, migration of pain to the right lower quadrant, vomiting, and white blood cell (WBC) count higher than 12.0 × 10(9) /L. Applying the CDR in the development set selected 126 of 199 (63%) patients with negative or inconclusive US results for discharge without further imaging. This rule reduced the probability of appendicitis from 26% (51 of 199) in the total group of patients with negative or inconclusive US results to 12% (15 of 126) in the group that would be discharged based on the rule (p = 0.001). In the validation set (n = 120), the decision rule selected 72 (60%) patients for discharge and next-day reevaluation and reduced the probability of appendicitis from 20% (24 of 120) in the total group to 6% (4 of 72) in the patients selected on the rule (p = 0.001). The negative predictive value of the decision rule in the validation set was 94% (95% confidence interval [CI] = 87% to 98%). In comparison, the negative predictive value of CT in the same group was 99% (95% CI = 93% to 100%, p = 0.14), and that of MRI was 99% (95% CI = 94% to 100%, p = 0.12). Alternative decision rules based on combinations of the present decision rule with C-reactive protein (CRP) results did not improve selection. This newly developed CDR significantly reduces the probability of appendicitis in a large subgroup of patients with negative or inconclusive US results. These patients can be safely discharged for outpatient reevaluation without further initial imaging if proper follow-up is available. This could assist in lowering the number of ED imaging investigations in patients with suspected appendicitis.

A cost-effective strategy for primary prevention of acute rheumatic fever and rheumatic heart disease in children with pharyngitis

Primary prevention of acute rheumatic fever (ARF) and rheumatic heart disease (RHD) in children depends on prompt and effective diagnosis and treatment of pharyngitis at the primary level of care. Cost-effectiveness modeling shows that the most cost-effective strategy for primary prevention in South Africa (SA) is to use a simple symptomatic clinical decision rule (CDR) to diagnose pharyngitis in children presenting at the primary level of care and then to treat them with a single dose of intramuscular penicillin. Treat All and CDR2+ strategies are affordable and simple and miss few cases of streptococcal pharyngitis at the primary level of care. The CDR2+ strategy is the most cost-effective for primary prevention of ARF and RHD in urban SA and should complement primordial and secondary prevention efforts.

Children with fever and cough at emergency care

To develop and validate a prediction model for the early identification of children with pneumonia in emergency care settings. This was a diagnostic study with derivation and validation of multivariate logistic regression models. This study was carried out on children aged 1 month-16 years presenting with fever and cough visiting the pediatric emergency department of the Erasmus MC-Sophia, Rotterdam, the Netherlands (derivation population, n=504); Pediatric Assessment Unit, University Hospitals Coventry and Warwickshire NHS Trust, UK (validation population 1, n=420); Accident & Emergency Department, Queen's Medical Centre, Nottingham, UK (validation population 2, n=366). The outcome pneumonia is defined by the presence of pulmonary consolidations on chest radiograph or follow-up. In population 1, 78 (16%) children were diagnosed with pneumonia; in populations 2 and 3, this number was 58 (14%) and 27 (7%), respectively. A simple clinical decision rule on the basis of ill appearance, tachypnea, decreased oxygen saturation, and elevated serum C-reactive protein categorized children as being at a low (<5%) or a high (>16%) risk of pneumonia. The rule yielded a discriminative value of 0.79 (0.69-0.89) in the Rotterdam population and was validated well in the other two populations. The risk of pneumonia can be assessed using three key clinical characteristics - overall assessment of the severity of illness, breathing rate, and oxygen saturation. Serum C-reactive protein contributes to the prediction of an intermediate risk of pneumonia in children. Children with a low risk of developing pneumonia with vital signs in the normal range can be discharged with effective safety netting, requiring neither antibiotics nor radiographs.

Abstract 55: Reducing Utilization of Cardiac Stress Testing in the Outpatient Primary Care Setting: a Clinical Prediction Rule

Background: Utilization of stress testing with imaging has significantly increased over the past decade. A simple clinical decision rule to guide stress test ordering for diagnosis of diagnose ischemia in the primary care setting could significantly reduce unnecessary utilization and health care costs. Methods: We retrospectively identified 495 outpatients without coronary artery disease (CAD) referred from primary care clinics who underwent stress echocardiography at a single US institution from 2007-2009. Predictors of echocardiographic ischemia were determined by logistical regression. From the predictor variables, a simple clinical decision rule was derived. The rule stratified individuals into 2 groups: subjects who should proceed to stress testing (ST) and subjects who do not require a stress test (NST). A receiver-operator characteristic curve was constructed to determine the rule’s accuracy. Event-free (interim stroke, myocardial infarction, or death) survival between the ST and NST arms was compared by log rank test. The rule was validated in a set of 299 charts from a different US institution. Results: In the derivation cohort, 23 tests (4.6%) demonstrated echocardiographic evidence of ischemia. Univariate predictors included male sex (odds ratio (OR) 2.3), family history of early CAD (OR 2.1), any chest pain (OR 9.1), fatigue or shortness of breath (OR 2.04), and age &gt; 50 years (OR 4.4). All variables were retained for the clinical decision rule. The rule selected 183 (37%) of subjects for NST while maintaining 100% sensitivity for ischemia (c-statistic 0.71, P&lt;0.001). 24 adverse clinical events occurred during follow-up (median: 2.6 years). There were no significant differences in adverse outcomes between ST and NST groups (P=0.35). In the validation cohort, 60% of subjects were select for NST with no differences in event-free survival between groups (P=0.30). Conclusion: Our simple decision rule could significantly reduce the number of stress tests ordered by primary care physicians without compromising event-free survival. Further refinement and validation of this score in both retrospective and prospective studies is warranted.

Clinical decision rule to predict the presence of interstitial lung disease in systemic sclerosis

To develop a clinical decision rule to predict the presence of interstitial lung disease (ILD) in systemic sclerosis (SSc; scleroderma) and to estimate the prevalence of SSc-ILD. Patient data were extracted from the Canadian Scleroderma Research Group registry. Three algorithms for the clinical decision rule were considered based on lung auscultation, chest radiography (CXR), and % predicted forced vital capacity (FVC). High-resolution computed tomography (HRCT) scans were used as the gold standard to determine the diagnostic properties of the 3 algorithms. Multiple imputation was used to impute HRCT data when missing, thereby avoiding bias due to differential referral for HRCT. This study included 1,168 patients. Of the patients with HRCT scans, 65% had evidence of ILD, compared to 26% by physical examination and 22% by CXR. The FVC of those who did not have HRCT was 8.8% greater than those who did (95% confidence interval [95% CI] 6.0-11.6%). Algorithm A, which identified the presence of ILD based on crackles on lung auscultation and/or findings on CXR, had a likelihood ratio of 3.9, compared to 3.2 for Algorithm B (which included patients with FVC <70%) and 2.2 for Algorithm C (which included patients with FVC <80%). The prevalence of ILD in the cohort was estimated to be 52% (95% CI 46-59%). We developed a simple clinical decision rule to predict SSc-ILD with good test characteristics. The prevalence of ILD in a large, unselected SSc cohort was estimated to be 52%.

Development and Validation of a Clinical Decision Rule for the Diagnosis of Influenza

A clinical decision rule to improve the accuracy of a diagnosis of influenza could help clinicians avoid unnecessary use of diagnostic tests and treatments. Our objective was to develop and validate a simple clinical decision rule for diagnosis of influenza. We combined data from 2 studies of influenza diagnosis in adult outpatients with suspected influenza: one set in California and one in Switzerland. Patients in both studies underwent a structured history and physical examination and had a reference standard test for influenza (polymerase chain reaction or culture). We randomly divided the dataset into derivation and validation groups and then evaluated simple heuristics and decision rules from previous studies and 3 rules based on our own multivariate analysis. Cutpoints for stratification of risk groups in each model were determined using the derivation group before evaluating them in the validation group. For each decision rule, the positive predictive value and likelihood ratio for influenza in low-, moderate-, and high-risk groups, and the percentage of patients allocated to each risk group, were reported. The simple heuristics (fever and cough; fever, cough, and acute onset) were helpful when positive but not when negative. The most useful and accurate clinical rule assigned 2 points for fever plus cough, 2 points for myalgias, and 1 point each for duration <48 hours and chills or sweats. The risk of influenza was 8% for 0 to 2 points, 30% for 3 points, and 59% for 4 to 6 points; the rule performed similarly in derivation and validation groups. Approximately two-thirds of patients fell into the low- or high-risk group and would not require further diagnostic testing. A simple, valid clinical rule can be used to guide point-of-care testing and empiric therapy for patients with suspected influenza.

Clostridium difficile-associated disease and mortality among the elderly critically ill

: To describe the epidemiology of and to develop a simple 30-day mortality clinical decision rule among critically ill patients > or =65 yrs. Increasing incidence of hospitalizations with and emergence of hypervirulent epidemic strains have made Clostridium difficile-associated disease an important public health concern. Advanced age is a risk factor for development of and death from Clostridium difficile-associated disease. Intensive care unit patients with Clostridium difficile-associated disease have a high mortality, but neither the burden of nor risk factors for death among the elderly intensive care unit patients with Clostridium difficile-associated disease are well understood. : Secondary analysis of a retrospective cohort study. : All intensive care units at a single academic institution. : A total of 278 critically ill patients with Clostridium difficile-associated disease; n = 148 aged > or =65 yrs. : None in addition to routine intensive care unit care. : Univariate analyses were performed to compare characteristics and outcomes of the elderly vs. the younger groups, and elderly 30-day survivors with nonsurvivors. Multivariable logistic regression model was developed with 30-day mortality as a dependent variable. Covariates retained in the model were assigned weighted points to develop a 30-day mortality prediction score. Area under the receiver operating characteristics curve and cross-validation analyses evaluated the score characteristics. Elderly patients were 68% more likely to experience 30-day mortality than the younger group. Absence of chronic respiratory disease (R), age 75+ yrs (A), septic shock (S), and Acute Physiology and Chronic Health Evaluation II score 20+ (A) comprised the RASA score, whose receiver operating characteristics was 0.740; 95% Confidence Interval was 0.663-0.817. : Elderly patients represent approximately 50% of intensive care unit patients with Clostridium difficile-associated disease and have a higher 30-day mortality than younger patients. A simple prediction rule incorporating determinants of 30-day mortality easily available at the bedside may aid in optimizing treatment decisions in this growing population.

Safely Ruling Out Deep Venous Thrombosis in Primary Care

Up to 90% of patients referred for ultrasonography with suspected deep venous thrombosis (DVT) of the leg do not have the disease. To evaluate the safety and efficiency of using a clinical decision rule that includes a point-of-care d-dimer assay at initial presentation in primary care to exclude DVT. A prospective management study. Approximately 300 primary care practices in 3 regions of the Netherlands (Amsterdam, Maastricht, and Utrecht). 1028 consecutive patients with clinically suspected DVT. Patients were managed on the basis of the result of the clinical decision rule, which included a d-dimer result. Patients with a score of 3 or less were not referred for ultrasonography and received no anticoagulant treatment; patients with a score of 4 or more were referred for ultrasonography. The primary outcome was symptomatic, objectively confirmed, venous thromboembolism during 3-month follow-up. The mean age of the 1028 study patients was 58 years, and 37% of patients were men. A valid score was obtained in 1002 patients (98%). In 500 patients (49%), with a score of 3 or less, 7 developed venous thromboembolism within 3 months (incidence, 1.4% [95% CI, 0.6% to 2.9%]). A total of 502 patients (49%) had a score of 4 or more; 3 did not have ultrasonography. Ultrasonography showed DVT in 125 patients (25%), for an overall prevalence in evaluable patients of 13% (125 of 1002). Of the 374 patients who had normal ultrasonography results, 4 developed venous thromboembolism within 3 months (1.1% [CI, 0.3% to 2.7%]). The study lacked a randomized design and relied on clinical follow-up to detect missed thrombotic disease. A diagnostic management strategy in primary care by using a simple clinical decision rule and a point-of-care d-dimer assay reduces the need for referral to secondary care of patients with clinically suspected DVT by almost 50% and is associated with a low risk for subsequent venous thromboembolic events. The Netherlands Organization for Scientific Research.

A Clinical Decision Rule to Aid Ordering of Serum and Urine Protein Electrophoresis for Case-Finding of Paraproteins in Hospitalized Inpatients

To develop a simple clinical decision rule that could increase the yield of serum and urine protein electrophoresis (SPE/UPE) without loss of sensitivity. A cross-sectional study of inpatients with a SPE/UPE performed over a 5-year period (2001-2006) with complete data on electrolytes, globulins, full blood count, creatinine, age, and gender. A tertiary-care general teaching hospital serving the Hunter Valley in New South Wales, with a referral population of over 1 million. A total of 14,374 adult patients admitted between January 2001-November 2006. Paraprotein on serum and/or urine protein electrophoresis (SPE/UPE). Five points were assigned for globulin > 41 g/l, 3 points for age > or = 60, 2 points for each of hemoglobin < 121 and male gender, and 1 point for estimated glomerular filtration rate (eGFR) < 60. Total scores of 0-5, 6-10, and > or = 11 corresponded to positive likelihood ratios of an abnormal SPE/UPE of 1, 2.5, and 6.6, respectively. The predictive ability of this model was strong, with an area under the curve of approximately 0.8. Results in the validation set were almost identical. A clinical decision rule using simple clinical variables has the potential to improve the yield of SPE/UPE. This rule however needs to be verified prospectively.

Observer performance in diagnosing osteoporosis by dental panoramic radiographs: Results from the osteoporosis screening project in dentistry (OSPD)

Mandibular cortical erosion detected on dental panoramic radiographs (DPRs) may be useful for identifying women with osteoporosis, but little is known about the variation in diagnostic efficacy of observers worldwide. The purpose of this study was to measure the accuracy in identifying women at risk for osteoporosis in a worldwide group of observers using DPRs. We constructed a website that included background information about osteoporosis screening and instructions regarding the interpretation of mandibular cortical erosion. DPRs of 100 Japanese postmenopausal women aged 50 years or older who had completed skeletal bone mineral measurements by dual energy X-ray absorptiometry were digitized at 300 dpi. These were displayed on the website and used for the evaluation of diagnostic efficacy. Sixty observers aged 25 to 66 years recruited from 16 countries participated in this study. These observers classified cortical erosion into one of three groups (none, mild to moderate, and severe) on the website via the Internet, twice with an approximately 2-week interval. The diagnostic efficacy of the Osteoporosis Self-Assessment Tool (OST), a simple clinical decision rule based on age and weight, was also calculated and compared with that of cortical erosion. The overall mean sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the 60 observers in identifying women with osteoporosis by cortical erosion on DPRs were 82.5, 46.2, 46.7, and 84.0%, respectively. Those same values by the OST index were 82.9, 43.1, 43.9, and 82.4%, respectively. The intra-observer agreement in classifying cortical erosion on DPRs was sufficient (weighted kappa values>0.6) in 36 (60%) observers. This was significantly increased in observers who specialized in oral radiology (P<0.05). In the 36 observers with sufficient intra-observer agreement, the overall mean sensitivity, specificity, PPV, and NPV in identifying women with osteoporosis by any cortical erosion were 83.5, 48.7, 48.3, and 85.7%, respectively. The mean PPV and NPV were significantly higher in the 36 observers with sufficient intra-observer agreement than in the 24 observers with insufficient intra-observer agreement. Our results reconfirm the efficacy of cortical erosion findings in identifying postmenopausal women at risk for osteoporosis, among observers with sufficient intra-observer agreement. Information gathered from radiographic examination is at least as useful as that gathered from the OST index.

30: A Simple Clinical Decision Rule to Predict Bacterial Meningitis in Patients Presenting to the Emergency Department

30: A Simple Clinical Decision Rule to Predict Bacterial Meningitis in Patients Presenting to the Emergency Department

External validation of bedside prediction score for diagnosis of late-onset neonatal sepsis

To prospectively validate performance of a prediction score for diagnosis of late-onset neonatal sepsis (LNS) in a new patient population. Data were prospectively collected from March 2003 to May 2004. Newborns were enrolled if they were in the neonatal intensive care unit (NICU) between 2 and 90 days, and during the first episode of clinical sepsis suspected. LNS was defined as a positive blood or cerebrospinal fluid (CSF) culture, which became the criterion standard. A total of 105 neonates were evaluated for sepsis. Demographic characteristics were as follows: (mean (s.d.)) were gestational age (GA) 29 (3) weeks; birth weight (BW) 1232 (620) g and postnatal age 17.5 day (12). Thirty-five (33%) neonates had LNS (35 positive blood cultures; 2 positive CSF). No significant differences in GA, BW, gender, age and central line utilization were found between LNS positive and LNS negative groups. Using a cut-off score of < or = 3, the score predicted positive culture with sensitivity of 0.97 (95% confidence interval 0.85, 0.99) and a negative likelihood ratio of 0.07. The discrimination and calibration ability of LNS score was acceptable. A simple clinical decision rule previously developed to predict LNS performs equally in an independent population and NICU.