Diagnostic accuracy of clinical prediction rules to exclude acute coronary syndrome in the emergency department setting: a systematic review

Value of free/total prostate-specific antigen (f/t PSA) ratios for prostate cancer detection in patients with total serum prostate-specific antigen between 4 and 10 ng/mL: A meta-analysis

BACKGROUND

Prostate carcinoma is a common disease that occurs in men over 50 years old. Many studies have explored the effect of free/total prostate-specific antigen (f/t PSA) ratio in monitoring prostate cancer. We conducted a meta-analysis to identify the accuracy of the f/t PSA ratio in the diagnosis of prostate cancer in patients who have PSA levels of 4 to 10 ng/mL.

METHODS

Databases searched included PubMed and OVID databases, from inception to March 2017, after a systematical review, sensitivity, specificity, and other measures of accuracy of the f/t PSA ratio in the diagnosis of prostate cancer were pooled. We used summary receiver operating characteristic curves to summarize overall test performance.

RESULTS

Fifteen case-control studies from 14 articles were identified. The results indicated that the sensitivity of the f/t PSA ratio in the diagnosis of prostate cancer ranged from 0.5 to 0.94 (pooled sensitivity 0.70, 95% CI: 0.67-0.72), whereas its specificity ranged from 0.31 to 0.93 (pooled specificity 0.55, 95% CI: 0.57-0.60). The positive likelihood ratio was 1.85 (95% CI: 1.56-2.20), negative likelihood ratio was 0.42 (95% CI: 0.34-0.53), and diagnostic odds ratio was 4.81 (9.53% CI: 3.33-6.94).

CONCLUSIONS

The f/t PSA ratio determination has a low sensitivity and specificity for the diagnosis of prostate cancer; it would not be useful for the diagnosis of prostate cancer by itself. The results of f/t PSA ratio measurements should refer to the clinical manifestations and the results of conventional tests such as biopsies.

The value of 18F-FDG-PET/CT in the diagnosis of solitary pulmonary nodules: A meta-analysis

BACKGROUND

Solitary pulmonary nodules (SPNs) are common imaging findings. Many studies have indicated that F-fluorodeoxyglucose positron emission tomography/computed tomography (F-FDG-PET/CT) is an accurate test for distinguishing benign and malignant SPNs. The aim of this study was to investigate the value of F-FDG-PET/CT in the diagnosis of malignant SPNs.

METHODS

We systematically searched the PubMed and Embase databases up to March 2017, and published data on sensitivity, specificity, and other measures of diagnostic accuracy of F-FDG-PET/CT in the diagnosis of malignant SPNs were meta-analyzed. Statistical analyses were undertaken using Meta-DiSc 1.4 software and Stata version 12.0. The measures of accuracy of F-FDG-PET/CT in the diagnosis of malignant SPNs were pooled using random-effects models.

RESULTS

A total of 20 publications reporting 21 studies were identified. Pooled results indicated that F-FDG-PET/CT showed a diagnostic sensitivity of 0.89 (95% confidence interval [CI], 0.87-0.91) and a specificity of 0.70 (95% CI, 0.66-0.73). The positive likelihood ratio was 3.33 (95% CI, 2.35-4.71) and the negative likelihood ratio was 0.18 (95% CI, 0.13-0.25). The diagnostic odds ratio was 22.43 (95% CI, 12.55-40.07).

CONCLUSIONS

F-FDG-PET/CT showed insufficient sensitivity and specificity for diagnosing malignant SPNs; it cannot replace the "gold standard" pathology by resection or percutaneous biopsy. Larger studies are required for further evaluation.

[Intelligent systems tools in the diagnosis of acute coronary syndromes: A systemic review]

BACKGROUND

Acute myocardial infarction is the leading cause of non-communicable deaths worldwide. Its diagnosis is a highly complex task, for which modelling through automated methods has been attempted. A systematic review of the literature was performed on diagnostic tests that applied intelligent systems tools in the diagnosis of acute coronary syndromes.

METHODS

A systematic review of the literature is presented using Medline, Embase, Scopus, IEEE/IET Electronic Library, ISI Web of Science, Latindex and LILACS databases for articles that include the diagnostic evaluation of acute coronary syndromes using intelligent systems. The review process was conducted independently by 2 reviewers, and discrepancies were resolved through the participation of a third person. The operational characteristics of the studied tools were extracted.

RESULTS

A total of 35 references met the inclusion criteria. In 22 (62.8%) cases, neural networks were used. In five studies, the performances of several intelligent systems tools were compared. Thirteen studies sought to perform diagnoses of all acute coronary syndromes, and in 22, only infarctions were studied. In 21 cases, clinical and electrocardiographic aspects were used as input data, and in 10, only electrocardiographic data were used. Most intelligent systems use the clinical context as a reference standard. High rates of diagnostic accuracy were found with better performance using neural networks and support vector machines, compared with statistical tools of pattern recognition and decision trees.

CONCLUSIONS

Extensive evidence was found that shows that using intelligent systems tools achieves a greater degree of accuracy than some clinical algorithms or scales and, thus, should be considered appropriate tools for supporting diagnostic decisions of acute coronary syndromes.

Best Clinical Practice: Current Controversies in the Evaluation of Low-Risk Chest Pain with Risk Stratification Aids. Part 2

BACKGROUND

Chest pain accounts for 10% of emergency department (ED) visits annually, and many of these patients are admitted because of potentially life-threatening conditions. A substantial percentage of patients with chest pain are at low risk for a major cardiac adverse event (MACE).

OBJECTIVE

We investigated controversies in the evaluation of patients with low-risk chest pain, including clinical scores, decision pathways, and shared decision-making.

DISCUSSION

ED patients with chest pain who have negative biomarker results and nonischemic electrocardiograms are at low risk for MACE. With the large number of chest pain patients evaluated in the ED, several risk scores and pathways are in use based on history, electrocardiographic results, and biomarker results. The Thrombolysis in Myocardial Infarction and Global Registry of Acute Coronary Events scores are older rules with validation; however, they do not have adequate sensitivity or are not easy to use in the ED. The Vancouver chest pain and North American chest pain rules may be used for patients with undifferentiated chest pain in the ED. The Manchester Acute Coronary Syndromes rule uses eight factors, several of which are not available in the United States. The history, electrocardiography, age, risk factors, and troponin (HEART) score and pathway are easy to use, have high sensitivity and negative predictive values, and have better discriminatory capability for categorization. The use of pathways with shared decision-making involves the patient in management, shortens the duration of stay, and decreases risk to both the patient and the provider.

CONCLUSIONS

Risk stratification of ED patients with chest pain has evolved, and there are many tools available. The HEART pathway, designed for ED use, has several attributes that provide safe and efficient care for patients with chest pain.

Determining 1-Yr Prosthetic Use for Mobility Prognoses for Community-Dwelling Adults with Lower-Limb Amputation: Development of a Clinical Prediction Rule

OBJECTIVE

The objective of this study was to develop a prognostic clinical prediction rule to identify people not achieving community walking level prosthetic use after 1 yr.

DESIGN

This is a prospective longitudinal cohort study of community-dwelling adults with lower-limb amputations recruited from support groups and prosthetic clinics. Participants completed Activities-specific Balance Confidence and Houghton prosthetic use for mobility self-report scales and the Berg Balance Scale. The clinical prediction rule was developed using multivariate logistic regression, receiver operating curves, and probability statistics to identify people not achieving community walking level prosthetic use (Houghton scores <9) at 1 yr.

RESULTS

Forty (74.1%) of 54 participants provided follow-up data. Participants averaged 57.0 ± 11.9 yrs old, and the most recent amputation had occurred an average of 6.6 ± 11.0 yrs ago. Seventy percent had vascular amputations and 52.5% had transtibial amputations. The clinical prediction rule predicted who would not reach the community prosthetic walking level with excellent accuracy (area under the curve >0.96) using four criteria: initial Houghton, Activities-specific Balance Confidence, and Berg Balance Scale tasks 9 (retrieve object from floor) and 10 (look behind over shoulders). Failure to exceed cutoff scores in two or more criteria yielded posttest probability of not reaching community walking prosthetic use 1 yr later for 90% of participants or higher.

CONCLUSIONS

Accurate 1-yr prosthetic use for mobility prognoses can be obtained by screening prosthetic use, balance confidence, and balance ability to identify community-dwelling people with lower-limb amputations unlikely to achieve community walking prosthetic use.

The clinics of acute coronary syndrome

Risk stratification and management of patients with chest pain continues to be challenging despite considerable efforts made in the last decades by many clinicians and researchers. The throutful evaluation necessitates that the physicians have a high index of suspicion for acute coronary syndrome (ACS) and always keep in mind the myriad of often subtle and atypical presentations of ischemic heart disease, especially in certain patient populations such as the elderly ones. In this article we aim to review and discuss the available evidence on the value of clinical presentation in patients with a suspected ACS, with special emphasis on history, characteristics of chest pain, associated symptoms, atypical presentations, precipitating and relieving factors, drugs, clinical rules and significance of clinical Gestalt.

Clinical assessment of patients with chest pain; a systematic review of predictive tools

Background

The clinical assessment of patients with chest pain of recent onset remains difficult. This study presents a critical review of clinical predictive tools for the assessment of patients with chest pain.

Methods

Systematic review of observational studies and estimation of probabilities of coronary artery disease (CAD) in patients with chest pain. Searches were conducted in PubMed, Embase, Scopus, and Web of Science to identify studies reporting tools, with at least three variables from clinical history, physical examination or ECG, produced with multivariate analysis, to estimate probabilities of CAD in patients with chest pain of recent onset, published from inception of the database to the 31^st July 2015. The references of previous relevant reviews were hand searched. The methodological quality was assessed with standard criteria. Since the incidence of CAD has changed in the past few decades, the date of publication was acknowledged to be relevant in order to use the tool in clinical practice, and more recent papers were considered more relevant. Probabilities of CAD according to the studies of highest quality were estimated and the evidence provided was graded.

Results

Twelve papers were included out of the 19126 references initially identified. The methodological quality of all of them was high. The clinical characteristics of the chest pain, age, past medical history of cardiovascular disease, gender, and abnormalities in the ECG were the predictors of CAD most commonly reported across the studies. The most recent papers, with highest methodological quality, and most practical for use in clinical settings, reported prediction or exclusion of CAD with area under the curve 0.90 in Primary Care, 0.91 in Emergency department, and 0.79 in Cardiology. These papers provide evidence of high level (1B) and the recommendation to use their results in the management of patients with chest pain is strong (A).

Conclusions

The risk of CAD can be estimated on clinical grounds in patients with chest pain in different clinical settings with high accuracy. The estimation of probabilities of CAD presented in these studies could be used for a better management of patients with chest pain and also in the development of future predictive tools.

Electronic supplementary material

The online version of this article (doi:10.1186/s12872-016-0196-4) contains supplementary material, which is available to authorized users.

Diagnostic accuracy of pleural fluid tumor necrosis factor-α in tuberculous pleurisy: A meta-analysis

BACKGROUND

Pleurisy is a common extra pulmonary complication of tuberculosis, but current methods for diagnosing it are fairly crude. Here we product a meta-analysis for the available evidence on the ability of tumor necrosis factor-α (TNF-α) in pleural fluid to serve as a diagnostic marker of tuberculous pleurisy (TP).

MATERIALS AND METHODS

We searched the PubMed, EMBASE, and Google Scholar databases systematically for studies measuring sensitivity, specificity and other measures of diagnostic accuracy of pleural fluid TNF-α in the diagnosis of TP were meta-analyzed by Stata, version 12 and meta-disc.

RESULTS

A total of six publications reporting seven case-control studies were identified. Pooled results indicated that pleural fluid TNF-α showed a diagnostic sensitivity of 0.89 (95% confidence interval [95% CI] 0.83-0.93; range, 0.42-1.0) and a diagnostic specificity of 0.82 (95% CI: 0.78-0.86; range, 0.58-0.98). The pooled positive likelihood ratio was 4.78 (95% CI: 3.32-6.89); the negative likelihood ratio, 0.16 (95% CI: 0.1-0.27); the diagnostic odds ratio, 32.43 (95% CI: 14.48-72.6); and the area under the curve was 0.8556 (standard error of mean 0.0559).

CONCLUSION

Pleural fluid TNF-α levels shows relatively high sensitivity but insufficient specificity for diagnosing TP. Pleural fluid TNF-α measurement may be useful in combination with clinical manifestations and conventional tests such as microbiological examination or pleural biopsy.

A systematic review of diagnostic performance of quantitative tests to assess musculoskeletal disorders in hand-arm vibration syndrome

The purpose was to systematically review the published reports for the clinical utility of quantitative objective tests commonly used for diagnosing musculoskeletal disorders in hand-arm vibration syndrome (HAVS). Two reviewers independently conducted a computerized literature search in PubMed and Scopus using predefined criteria, and relevant papers were identified. The articles were screened in several stages and considered for final inclusion. Quality of the selected papers was evaluated by a modified QUADAS tool. Relevant data were extracted as necessary. For this review, only 4 relevant studies could be identified for detailed examination. Grip strength, pinch strength, and Purdue pegboard tests were commonly used with their reported sensitivity and specificity ranging between 1.7 to 65.7% and 65.2 to 100%, 1.7 to 40% and 94 to 100%, and 44.8 to 85% and 78 to 95%, respectively. A considerable difference across the studies was observed with respect to patient and control populations, diagnostic performance and cut-off values of different tests. Overall, currently available English-language limited literature do not provide enough evidence in favour of the application of grip strength and pinch strength tests for diagnosing musculoskeletal injuries in HAVS; Purdue pegboard test seems to have some diagnostic value in evaluating impaired dexterity in HAVS.

Diagnostic values of chest pain history, ECG, troponin and clinical gestalt in patients with chest pain and potential acute coronary syndrome assessed in the emergency department

In the assessment of chest pain patients with suspected acute coronary syndrome (ACS) in the emergency department (ED), physicians rely on global diagnostic impressions (‘gestalt’). The aim of this study was to determine the diagnostic value of the ED physician’s overall assessment of ACS likelihood, and the values of the main diagnostic modalities underlying this assessment, namely the chest pain history, the ECG and the initial troponin result. 1,151 consecutive ED chest pain patients were prospectively included. The ED physician’s interpretation of the chest pain history, the ECG, and the global likelihood of ACS were recorded on special forms. The discharge diagnoses were retrieved from the medical records. A chart review was carried out to determine whether patients with a non-ACS diagnosis at the index visit had ACS or suffered cardiac death within 30 days. The gestalt was better than its components both at ruling in (“Obvious ACS”, LR 29) and at ruling out (“No Suspicion of ACS”, LR 0.01) ACS. In the “Strong suspicion of ACS” group, 60% of the patients did not have ACS. A positive TnT (LR 24.9) and an ischemic ECG (LR 8.3) were strong predictors of ACS and seemed superior to pain history for ruling in ACS. In patients with a normal TnT and non-ischemic ECG, chest pain history typical of AMI was not a significant predictor of AMI (LR 1.9) while pain history typical of unstable angina (UA) was a moderate predictor of UA (LR 4.7). Clinical gestalt was better than its components both at ruling in and at ruling out ACS, but overestimated the likelihood of ACS when cases were assessed as strong suspicion of ACS. Among the components of the gestalt, TnT and ECG were superior to the chest pain history for ruling in ACS, while pain history was superior for ruling out ACS.

Management of acute chest pain: A major role for coronary CT angiography

Most patients presenting with acute chest pain (ACP) at the emergency unit do not have any marked electrocardiogram abnormalities or known history of heart disease. Identifying the few patients who have, or will actually develop acute coronary syndrome in this group that is considered to be at low risk, is an actual clinical challenge for emergency department physicians. In these patients, the goal of complementary non-invasive morphological or functional imaging tests is to exclude heart disease. The diagnostic values of coronary CT angiography include a sensitivity of 96% and a negative likelihood ratio of 0.09, which are highly contributory to the diagnosis, and the integration of this imaging test into a decision tree algorithm appears to be the least expensive strategy with the best cost/effective ratio. Coronary CT angiography is indicated in the presence of ACP associated with an inconclusive electrocardiogram, in the absence of any other obvious diagnoses, when the ultrasensitive troponin assay is negative or the dynamic changes are modest, slow and/or inconclusive. Ideally, coronary CT angiography should be performed within 3 to 48hours after the initial consultation.

Development and validation of a prediction rule for early discharge of low-risk emergency department patients with potential ischemic chest pain

Objectives:

Current guidelines emphasize that emergency department (ED) patients at low risk for potential ischemic chest pain cannot be discharged without extensive investigations or hospitalization to minimize the risk of missing acute coronary syndrome (ACS). We sought to derive and validate a prediction rule that permitted 20 to 30% of ED patients without ACS safely to be discharged within 2 hours without further provocative cardiac testing.

Methods:

This prospective cohort study enrolled 1,669 chest pain patients in two blocks in 2000–2003 (development cohort) and 2006 (validation cohort). The primary outcome was 30-day ACS diagnosis. A recursive partitioning model incorporated reliable and predictive cardiac risk factors, pain characteristics, electrocardiographic findings, and cardiac biomarker results.

Results:

In the derivation cohort, 165 of 763 patients (21.6%) had a 30-day ACS diagnosis. The derived prediction rule was 100.0% sensitive and 18.6% specific. In the validation cohort, 119 of 906 patients (13.1%) had ACS, and the prediction rule was 99.2% sensitive (95% CI 95.4–100.0) and 23.4% specific (95% CI 20.6–26.5). Patients have a very low ACS risk if arrival and 2-hour troponin levels are normal, the initial electrocardiogram is nonischemic, there is no history of ACS or nitrate use, age is &lt; 50 years, and defined pain characteristics are met. The validation of the rule was limited by the lack of consistency in data capture, incomplete follow-up, and lack of evaluation of the accuracy, comfort, and clinical sensibility of this clinical decision rule.

Conclusion:

The Vancouver Chest Pain Rule may identify a cohort of ED chest pain patients who can be safely discharged within 2 hours without provocative cardiac testing. Further validation across other centres with consistent application and comprehensive and uniform follow-up of all eligible and enrolled patients, in addition to measuring and reporting the accuracy of and comfort level with applying the rule and the clinical sensibility, should be completed prior to adoption and implementation.

The value of signs, symptoms and plasma heart-type fatty acid-binding protein (H-FABP) in evaluating patients presenting with symptoms possibly matching acute coronary syndrome: background and methods of a diagnostic study in primary care

Background

Chest complaints presented to a general practitioner (GP) are frequently caused by diseases which have advantageous outcomes. However, in some cases, acute coronary syndrome (ACS) is present (1.5-22% of cases). The patient’s signs, symptoms and electrocardiography results are insufficient diagnostic tools to distinguish mild disease from ACS. Therefore, most patients presenting chest complaints are referred to secondary care facilities where ACS is then ruled out in a majority of patients (78%). Recently, a point of care test for heart-type fatty acid-binding protein (H-FABP) using a low cut-off value between positive and negative of 4 ng/ml has become available. We aim to study the role of this point of care device in triage of patients presenting chest complaints possibly due to ACS, in primary care. Our research protocol is presented in this article. Results are expected in 2015.

Methods/Design

Participating GPs will register signs and symptoms in all patients presenting chest complaints possibly due to ACS. Point of care H-FABP testing will also be performed. Our study will be a derivation study to identify signs and symptoms that, combined with point of care H-FABP testing, can be part of an algorithm to either confirm or rule out ACS. The diagnostic value for ACS of this algorithm in general practice will be determined.

Discussion

A safe diagnostic elimination of ACS by application of the algorithm can be of significant clinical relevance. Improved triage and thus reduction of the number of patients with chest complaints without underlying ACS, that are referred to secondary care facilities, could lead to a substantial cost reduction.

Trial registration

ClinicalTrials.gov, NCT01826994, accepted April 8^th 2013.

Critical appraisal and data extraction for systematic reviews of prediction modelling studies: the CHARMS checklist

Carl Moons and colleagues provide a checklist and background explanation for critically appraising and extracting data from systematic reviews of prognostic and diagnostic prediction modelling studies. Please see later in the article for the Editors' Summary.

Out-of-hours exercise treadmill testing reduces length of hospital stay for chest pain admissions

AIMS

The objective was to examine the impact of out-of-hours exercise treadmill tests (ETTs) on length of hospital stay (LOS) for patients admitted to a chest pain assessment unit with symptoms suggestive of acute coronary syndrome.

METHODS

Prospective observational study with 30-day follow-up of low-to-intermediate-risk chest pain patients undergoing out-of-hours ETT. Eligible patients had a nonischemic ECG, normal 6-12-h ST-segment monitoring, a negative 12-h troponin T assay, and no contraindications to exercise. Observed LOS was compared to expected LOS in the absence of out-of-hours ETT, using Wilcoxon rank-sum test. Estimated bed day savings and major adverse events at 30 days after discharge were examined.

RESULTS

Four hundred and twenty-two patients with a mean age of 52 years (SD 13 years, 25-83 years) were evaluated. Fifty-two per cent (n = 221) were men; 66% (n = 279) had one or less cardiovascular risk factors; and 79% (n = 334) of the patients presented on a Friday or Saturday. ETT was performed on a weekend day in 86% (n = 363) of the patients, facilitating same-day discharges in 71% (n =  300). The median LOS (interquartile range) was 1 day (1, 2 days) for patients assessed with out-of-hours ETT. The expected median LOS (IQR) was 3 days (2, 4 days) (P < 0.05) in the absence of out-of-hours ETT. Each out-of-hours ETT was estimated to save a mean (SD, range) of 1.6 (0.6, 1-4) bed days. Thirty-day mortality and readmission rates were 0 and 0.2% (1 of 422), respectively.

CONCLUSION

The availability of out-of-hours ETT facilitates safe early discharge and reduced LOS for low-to-moderate-risk patients admitted with symptoms of acute coronary syndrome.

Evaluation and outcomes of patients admitted to a tertiary medical assessment unit with acute chest pain of possible coronary origin

OBJECTIVES

The study aims to (i) profile clinical characteristics, risk estimates of acute coronary syndrome (ACS), use and yield of non-invasive cardiac testing, discharge diagnosis and 30-day outcomes among patients admitted with acute chest pain of possible coronary origin; and (ii) construct a risk stratification algorithm that informs management decisions.

METHODS

This is a retrospective cohort study of 130 consecutive patients admitted to a tertiary hospital medical assessment unit between 24 January and 22 March 2012. Estimates of ACS risk were based on Australian guidelines and Thrombolysis in Myocardial Infarction (TIMI) scores.

RESULTS

Patients were of mean age 61 years, 45% had known coronary artery disease (CAD), 58% presented with typical ischaemic pain, 82% had intermediate to high ACS risk and 61% underwent testing. Myocardial ischaemia was cardiologist-confirmed discharge diagnosis in 29% of patients, and was associated with known CAD, typical pain, multiple risk factors and high TIMI risk scores (P < 0.001 for all associations). Of 98 non-invasive investigations, 9% (95% CI, 5-17%) were positive for myocardial ischaemia. Major adverse event rate at 30 days was 0.8% (95% CI, <0.1-6%). An algorithm was constructed that integrates known CAD, ACS risk and TIMI scores in identifying low-risk patients capable of rapid discharge from EDs without further investigation, and classifying the remainder into risk groups that informs choice of investigations and need for telemetry.

CONCLUSIONS

In patients with indeterminate chest pain, clinical features and risk scores identify most with myocardial ischaemia. An algorithm is presented that might inform triaging, early discharge, choice of testing and need for telemetry.

Does this child have appendicitis? A systematic review of clinical prediction rules for children with acute abdominal pain

OBJECTIVES

To systematically identify clinical prediction rules (CPRs) for children with suspected appendicitis and compare their methodological quality and performance.

STUDY DESIGN AND SETTING

Included studies involved children aged 0-18 years with suspected appendicitis identified through MEDLINE and EMBASE from 1950 to 2012. The quality was assessed using 17 previously published items. The performance was evaluated using the sensitivity, negative likelihood ratio, and predicted frequency of appendicitis diagnosis that would result if the rule was used.

RESULTS

Twelve studies fulfilled the inclusion criteria describing the derivation or validation of six unique CPRs involving 4,201 children with suspected appendicitis. Migratory pain, nausea or vomiting, and right lower quadrant tenderness were common predictors to all rules. Methodological quality varied widely. The most poorly addressed quality items were the predictor and outcome assessor blinding, predictor description, and reproducibility of predictor assessment. The most well-validated CPRs were the Pediatric Appendicitis Score (PAS) and MANTRELS (Migration, Anorexia, Nausea/vomiting, Tenderness in the right lower quadrant, Rebound pain, Elevation in temperature, Leukocytosis, Shift to the left)/Alvarado Score. Overall, the PAS validation studies outperformed the Alvarado validation studies.

CONCLUSION

The PAS and Alvarado scores were the most well validated but neither met the current performance benchmarks. A high quality, well validated, and consistently high-performing CPR was not identified. Further research is needed before a CPR for children with suspected appendicitis can be used in routine practice.

Diagnostic accuracy of prehospital clinical prediction models to identify short-term outcomes in patients with acute coronary syndromes: a systematic review

BACKGROUND

Although cardiac risk prediction is widely used in various clinical settings, its potential role in enhancing prehospital triage is yet to be understood.

OBJECTIVE

To systematically review the diagnostic accuracy of short-term clinical prediction models for potential use in a prehospital population with suspected acute coronary syndrome.

METHODS

Eleven electronic medical databases were searched from 1990 to the end of August 2010 for all English-language observational and interventional studies. An online search strategy tool was used to identify grey-literature studies. Eligibility criteria were: 1) an unselected population of adult acute coronary syndrome patients; 2) recruited within the Emergency Department or Emergency Medical Services; 3) reported multivariate analysis encompassing patient history or physical examination; 4) reported short-term outcome measures; 5) were not solely computer protocols; and 6) were not reliant on tests unavailable out of the hospital. Data extraction was conducted by a single reviewer and verified by a second reviewer. Study quality was assessed independently by two reviewers using a validated quality assessment tool.

RESULTS

A total of seven clinical prediction models were identified. Only two models reported were derived from a prehospital study population. Six clinical prediction models described good discriminate abilities (c-statistic) of 0.72 to 0.87. Among the range of independent predictors identified, electrocardiogram abnormalities, age, heart rate, and systolic blood pressure provided the strongest prognostic information.

CONCLUSION

The models identified provided reasonable diagnostic accuracy for determining short-term outcomes. Methodological weaknesses and variability in the populations investigated limit their use in clinical practice.

Ruling out coronary heart disease in primary care: external validation of a clinical prediction rule

BACKGROUND

The Marburg Heart Score (MHS) aims to assist GPs in safely ruling out coronary heart disease (CHD) in patients presenting with chest pain, and to guide management decisions.

AIM

To investigate the diagnostic accuracy of the MHS in an independent sample and to evaluate the generalisability to new patients.

DESIGN AND SETTING

Cross-sectional diagnostic study with delayed-type reference standard in general practice in Hesse, Germany.

METHOD

Fifty-six German GPs recruited 844 males and females aged ≥ 35 years, presenting between July 2009 and February 2010 with chest pain. Baseline data included the items of the MHS. Data on the subsequent course of chest pain, investigations, hospitalisations, and medication were collected over 6 months and were reviewed by an independent expert panel. CHD was the reference condition. Measures of diagnostic accuracy included the area under the receiver operating characteristic curve (AUC), sensitivity, specificity, likelihood ratios, and predictive values.

RESULTS

The AUC was 0.84 (95% confidence interval [CI] = 0.80 to 0.88). For a cut-off value of 3, the MHS showed a sensitivity of 89.1% (95% CI = 81.1% to 94.0%), a specificity of 63.5% (95% CI = 60.0% to 66.9%), a positive predictive value of 23.3% (95% CI = 19.2% to 28.0%), and a negative predictive value of 97.9% (95% CI = 96.2% to 98.9%).

CONCLUSION

Considering the diagnostic accuracy of the MHS, its generalisability, and ease of application, its use in clinical practice is recommended.

Improving risk stratification in patients with chest pain: the Erlanger HEARTS3 score

BACKGROUND

The HEART score uses elements from patient History, Electrocardiogram, Age, Risk Factors, and Troponin to obtain a risk score on a 0- to 10-point scale for predicting acute coronary syndromes (ACS). This investigation seeks to improve on the HEART score by proposing the HEARTS(3) score, which uses likelihood ratio analysis to give appropriate weight to the individual elements of the HEART score as well as incorporating 3 additional "S" variables: Sex, Serial 2-hour electrocardiogram, and Serial 2-hour delta troponin during the initial emergency department valuation.

METHODS

This is a retrospective analysis of a prospectively acquired database consisting of 2148 consecutive patients with non-ST-segment elevation chest pain. Interval analysis of likelihood ratios was performed to determine appropriate weighting of the individual elements of the HEART(3) score. Primary outcomes were 30-day ACS and myocardial infarction.

RESULTS

There were 315 patients with 30-day ACS and 1833 patients without ACS. Likelihood ratio analysis revealed significant discrepancies in weight of the 5 individual elements shared by the HEART and HEARTS(3) score. The HEARTS(3) score outperformed the HEART score as determined by comparison of areas under the receiver operating characteristic curve for myocardial infarction (0.958 vs 0.825; 95% confidence interval difference in areas, 0.105-0.161) and for 30-day ACS (0.901 vs 0.813; 95% confidence interval difference in areas, 0.064-0.110).

CONCLUSION

The HEARTS(3) score reliably risk stratifies patients with chest pain for 30-day ACS. Prospective studies need to be performed to determine if implementation of this score as a decision support tool can guide treatment and disposition decisions in the management of patients with chest pain.

CT angiography for safe discharge of patients with possible acute coronary syndromes

BACKGROUND

Admission rates among patients presenting to emergency departments with possible acute coronary syndromes are high, although for most of these patients, the symptoms are ultimately found not to have a cardiac cause. Coronary computed tomographic angiography (CCTA) has a very high negative predictive value for the detection of coronary disease, but its usefulness in determining whether discharge of patients from the emergency department is safe is not well established.

METHODS

We randomly assigned low-to-intermediate-risk patients presenting with possible acute coronary syndromes, in a 2:1 ratio, to undergo CCTA or to receive traditional care. Patients were enrolled at five centers in the United States. Patients older than 30 years of age with a Thrombolysis in Myocardial Infarction risk score of 0 to 2 and signs or symptoms warranting admission or testing were eligible. The primary outcome was safety, assessed in the subgroup of patients with a negative CCTA examination, with safety defined as the absence of myocardial infarction and cardiac death during the first 30 days after presentation.

RESULTS

We enrolled 1370 subjects: 908 in the CCTA group and 462 in the group receiving traditional care. The baseline characteristics were similar in the two groups. Of 640 patients with a negative CCTA examination, none died or had a myocardial infarction within 30 days (0%; 95% confidence interval [CI], 0 to 0.57). As compared with patients receiving traditional care, patients in the CCTA group had a higher rate of discharge from the emergency department (49.6% vs. 22.7%; difference, 26.8 percentage points; 95% CI, 21.4 to 32.2), a shorter length of stay (median, 18.0 hours vs. 24.8 hours; P<0.001), and a higher rate of detection of coronary disease (9.0% vs. 3.5%; difference, 5.6 percentage points; 95% CI, 0 to 11.2). There was one serious adverse event in each group.

CONCLUSIONS

A CCTA-based strategy for low-to-intermediate-risk patients presenting with a possible acute coronary syndrome appears to allow the safe, expedited discharge from the emergency department of many patients who would otherwise be admitted. (Funded by the Commonwealth of Pennsylvania Department of Health and the American College of Radiology Imaging Network Foundation; ClinicalTrials.gov number, NCT00933400.).

Clinical prediction rules for children: a systematic review

CONTEXT

The degree to which clinical prediction rules (CPRs) for children meet published standards is unclear.

OBJECTIVE

To systematically review the quality, performance, and validation of published CPRs for children, compare them with adult CPRs, and suggest pediatric-specific changes to CPR methodology.

METHODS

Medline was searched from 1950 to 2011. Studies were selected if they included the development of a CPR involving children younger than 18 years. Two investigators assessed study quality, rule performance, and rule validation as methodologic standards.

RESULTS

Of 7298 titles and abstracts assessed, 137 eligible studies were identified. They describe the development of 101 CPRs addressing 36 pediatric conditions. Quality standards met in fewer than half of the studies were blind assessment of predictors (47%), reproducibility of predictors (18%), blind assessment of outcomes (42%), adequate follow-up of outcomes (36%), adequate power (43%), adequate reporting of results (49%), and 95% confidence intervals reported (36%). For rule performance, 48% had a sensitivity greater than 0.95, and 43% had a negative likelihood ratio less than 0.1. For rule validation, 76% had no validation, 17% had narrow validation, 8% had broad validation, and none had impact analysis performed. Compared with CPRs for adult health conditions, quality and rule validation seem to be lower.

CONCLUSIONS

Many CPRs have been derived for children, but few have been validated. Relative to adult CPRs, several quality indicators demonstrated weaknesses. Existing performance standards may prove elusive for CPRs that involve children. CPRs for children that are more assistive and less directive and include patients' values and preferences in decision-making may be helpful.

Clinical prediction rules in the physiotherapy management of low back pain: a systematic review

OBJECTIVE

To identify, appraise and determine the clinical readiness of diagnostic, prescriptive and prognostic Clinical Prediction Rules (CPRs) in the physiotherapy management of Low Back Pain (LBP).

DATA SOURCES

MEDLINE, EMBASE, CINAHL, AMED and the Cochrane Database of Systematic Reviews were searched from 1990 to January 2010 using sensitive search strategies for identifying CPR and LBP studies. Citation tracking and hand-searching of relevant journals were used as supplemental strategies.

STUDY SELECTION

Two independent reviewers used a two-phase selection procedure to identify studies that explicitly aimed to develop one or more CPRs involving the physiotherapy management of LBP. Diagnostic, prescriptive and prognostic studies investigating CPRs at any stage of their development, derivation, validation, or impact-analysis, were considered for inclusion using a priori criteria. 7453 unique records were screened with 23 studies composing the final included sample.

DATA EXTRACTION

Two reviewers independently extracted relevant data into evidence tables using a standardised instrument.

DATA SYNTHESIS

Identified studies were qualitatively synthesized. No attempt was made to statistically pool the results of individual studies. The 23 scientifically admissible studies described the development of 25 unique CPRs, including 15 diagnostic, 7 prescriptive and 3 prognostic rules. The majority (65%) of studies described the initial derivation of one or more CPRs. No studies investigating the impact phase of rule development were identified.

CONCLUSIONS

The current body of evidence does not enable confident direct clinical application of any of the identified CPRs. Further validation studies utilizing appropriate research designs and rigorous methodology are required to determine the performance and generalizability of the derived CPRs to other patient populations, clinicians and clinical settings.

Diagnosing acute coronary syndrome in primary care: comparison of the physicians' risk estimation and a clinical decision rule

BACKGROUND

Diagnosing acute coronary syndrome (ACS) in a primary care setting poses a diagnostic dilemma for physicians.

OBJECTIVE

We directly compared the diagnostic accuracy of a clinical decision rule (CDR) based on history taking and physical examination in suspected ACS with the risk estimates of the attending GP.

METHODS

In a prospective multicenter study, patients suspected of ACS were included by the GP. GPs were asked to estimate the probability (0%-100%) of the presence of ACS. GPs collected patient data, but they were not aware of the CDR and did not score the patient accordingly.

RESULTS

Two hundred and ninety-eight patients were included (52% female, mean age 66 years, 22% ACS). The area under the receiver operating characteristic (ROC) curve (AUC) was 0.75 [95% confidence interval (CI) 0.68-0.82] for the GP risk estimate and 0.66 (95% CI 0.58-0.73) for the CDR. There was an agreement between the risk estimation of the GP and a CDR in 51% and the prevalence of ACS in predefined low-, intermediate- and high-risk groups was similar for the GP and CDR estimates. In the low-risk group, according to the GP, four patients (8.2%) suffered an ACS. These four patients were all identified by the decision rule as high risk.

CONCLUSIONS

The GP classified patients as ACS or no ACS more adequately than the CDR, judged by the AUC. However, the use of a CDR in patients that are considered at low risk for ACS by the GP could reduce the amount of missed myocardial infarctions.

Derivation of a clinical decision rule for chest radiography in emergency department patients with chest pain and possible acute coronary syndrome

OBJECTIVE

We derived a clinical decision rule to determine which emergency department (ED) patients with chest pain and possible acute coronary syndrome (ACS) require chest radiography.

METHODS

We prospectively enrolled patients over 24 years of age with a primary complaint of chest pain and possible ACS over a 6 month period. Emergency physicians completed standardized clinical assessments and ordered chest radiographs as appropriate. Two blinded investigators independently classified chest radiographs as "normal," "abnormal not requiring intervention" and "abnormal requiring intervention," based on review of the radiology report and the medical record. The primary outcome was abnormality of chest radiographs requiring acute intervention. Analyses included interrater reliability assessment (with kappa statistics), univariate analyses and recursive partitioning.

RESULTS

We enrolled 529 patients during the study period between Jul. 1, 2007, and Dec. 31, 2007. Patients had a mean age of 59.9 years, 60.3% were male, 4.0% had a history of congestive heart failure and 21.9% had a history of acute myocardial infarction. Only 2.1% (95% confidence interval [CI] 1.1%-3.8%) of patients had radiographic abnormality of the chest requiring acute intervention. The kappa statistic for chest radiograph classification was 0.81 (95% CI 0.66-0.95). We derived the following rule: patients can forgo chest radiography if they have no history of congestive heart failure, no history of smoking and no abnormalities on lung auscultation. The rule was 100% sensitive (95% CI 32.0%-40.4%) and 36.1% specific (95% CI 32.0%-40.4%).

CONCLUSION

This rule has potential to reduce health care costs and enhance ED patient flow. It requires validation in an independent patient population before introduction into clinical practice.

Future developments in chest pain diagnosis and management

Much of the focus of research on patients with chest pain is directed at technological advances in the diagnosis and management of acute coronary syndrome (ACS), pulmonary embolism (PE), and acute aortic dissection (AAD), despite there being no significant difference at 4 years as regards mortality, ongoing chest pain, and quality of life between patients presenting to the emergency department with noncardiac chest pain and those with cardiac chest pain. This article examines future developments in the diagnosis and management of patients with suspected ACS, PE, AAD, gastrointestinal disease, and musculoskeletal chest pain.

Prospective validation of a modified thrombolysis in myocardial infarction risk score in emergency department patients with chest pain and possible acute coronary syndrome

OBJECTIVES

This study attempted to prospectively validate a modified Thrombolysis In Myocardial Infarction (TIMI) risk score that classifies patients with either ST-segment deviation or cardiac troponin elevation as high risk. The objectives were to determine the ability of the modified score to risk-stratify emergency department (ED) patients with chest pain and to identify patients safe for early discharge.

METHODS

This was a prospective cohort study in an urban academic ED over a 9-month period. Patients over 24 years of age with a primary complaint of chest pain were enrolled. On-duty physicians completed standardized data collection forms prior to diagnostic testing. Cardiac troponin T-values of >99th percentile (> or =0.01 ng/mL) were considered elevated. The primary outcome was acute myocardial infarction (AMI), revascularization, or death within 30 days. The overall diagnostic accuracy of the risk scores was compared by generating receiver operating characteristic (ROC) curves and comparing the area under the curve. The performance of the risk scores at potential decision thresholds was assessed by calculating the sensitivity and specificity at each potential cut-point.

RESULTS

The study enrolled 1,017 patients with the following characteristics: mean (+/-SD) age 59.3 (+/-13.8) years, 60.6% male, 17.9% with a history of diabetes, and 22.4% with a history of myocardial infarction. A total of 117 (11.5%) experienced a cardiac event within 30 days (6.6% AMI, 8.9% revascularization, 0.2% death of cardiac or unknown cause). The modified TIMI risk score outperformed the original with regard to overall diagnostic accuracy (area under the ROC curve = 0.83 vs. 0.79; p = 0.030; absolute difference 0.037; 95% confidence interval [CI] = 0.004 to 0.071). The specificity of the modified score was lower at all cut-points of >0. Sensitivity and specificity at potential decision thresholds were: >0 = sensitivity 96.6%, specificity 23.7%; >1 = sensitivity 91.5%, specificity 54.2%; and >2 = sensitivity 80.3%, specificity 73.4%. The lowest cut-point (TIMI/modified TIMI >0) was the only cut-point to predict cardiac events with sufficient sensitivity to consider early discharge. The sensitivity and specificity of the modified and original TIMI risk scores at this cut-point were identical.

CONCLUSIONS

The modified TIMI risk score outperformed the original with regard to overall diagnostic accuracy. However, it had lower specificity at all cut-points of >0, suggesting suboptimal risk stratification in high-risk patients. It also lacked sufficient sensitivity and specificity to safely guide patient disposition. Both scores are insufficiently sensitive and specific to recommend as the sole means of determining disposition in ED chest pain patients.