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1.  Accuracy and Quality of Clinical Decision Rules for Syncope in the Emergency Department: A Systematic Review and Meta-analysis 
Annals of emergency medicine  2010;56(4):362-373.e1.
Objectives
We assessed the methodological quality and prognostic accuracy of clinical decision rules (CDR) in emergency department (ED) syncope patients.
Methods
We searched 5 electronic databases, reviewed reference lists of included studies and contacted content experts to identify articles for review. Studies that derived or validated CDRs in ED syncope patients were included. Two reviewers independently screened records for relevance, selected studies for inclusion, assessed study quality and abstracted data. Random effects meta-analysis was used to pool diagnostic performance estimates across studies that derived or validated the same CDR. Between study heterogeneity was assessed with I-squared statistic (I2), and subgroup hypotheses were tested using a test of interaction.
Results
We identified 18 eligible studies. Deficiencies in outcome (blinding) and inter-rater reliability assessment were the most common methodological weaknesses. Meta-analysis of the San Francisco Syncope Rule (SFSR) [sensitivity 86% (95%CI 83-89); specificity 49% (95%CI 48-51)] and the Osservatorio Epidemiologico sulla Sincope nel Lazio (OESIL) risk score [sensitivity 95% (95%CI 88-98); specificity 31% (95%CI 29-34)]. Subgroup analysis identified study design [prospective, diagnostic odds ratio (DOR) 8.82 (95%CI 3.5-22) vs. retrospective, DOR 2.45 (95%CI 0.96-6.21)] and ECG determination [by evaluating physician, DOR 25.5 (95%CI 4.41-148) vs. researcher or cardiologist, DOR 4 (95%CI 2.15-7.55)] as potential explanations for the variability in SFSR performance.
Conclusion
The methodological quality and prognostic accuracy of CDRs for syncope is limited. Differences in study design and ECG interpretation may account for the variable prognostic performance of the SFSR when validated in different practice settings.
doi:10.1016/j.annemergmed.2010.05.013
PMCID: PMC2946941  PMID: 20868906
syncope; clinical decision rules
2.  Aspirin for the Primary Prevention of Cardiovascular Events 
Diabetes Care  2009;32(12):2300-2306.
OBJECTIVE
The negative results of two randomized controlled trials (RCTs) have challenged current guideline recommendations for using aspirin for primary prevention of cardiovascular events among patients with diabetes. We therefore sought to determine if the effect of aspirin for primary prevention of cardiovascular events and mortality differs between patients with and without diabetes.
RESEARCH DESIGN AND METHODS
We conducted a systematic search of MEDLINE, EMBASE, Cochrane Library, Web of Science, and Scopus since their inceptions until November 2008 for RCTs of aspirin for primary prevention of cardiovascular events. Blinded pairs of reviewers evaluated studies and extracted data. Random-effects meta-analysis and Bayesian logistic regression were used to estimate the ratios of relative risks (RRs) of outcomes of interest among patients with and without diabetes. A 95% CI that crosses 1.00 indicates that the effect of aspirin does not differ between patients with and without diabetes.
RESULTS
Nine RCTs with moderate to high methodological quality contributed data to the analyses. The ratios of RRs comparing the benefit of aspirin among patients with diabetes compared with patients without diabetes for mortality, myocardial infarction, and ischemic stroke were 1.12 (95% CI 0.92–1.35), 1.19 (0.82–1.17), and 0.70 (0.25–1.97), respectively.
CONCLUSIONS
Whereas estimates of benefit among patients with diabetes remain imprecise, our analysis suggests that the relative benefit of aspirin is similar in patients with and without diabetes.
doi:10.2337/dc09-1297
PMCID: PMC2782995  PMID: 19741185
3.  Diagnostic accuracy of the TIMI risk score in patients with chest pain in the emergency department: a meta-analysis 
Background
The Thrombolysis in Myocardial Infarction (TIMI) risk score uses clinical data to predict the short-term risk of acute myocardial infarction, coronary revascularization or death from any cause. It was originally developed for use in patients with unstable angina or non–ST-elevation myocardial infarction. We sought to expand the clinical application of the TIMI risk score by assessing its prognostic accuracy in patients in the emergency department with potential acute coronary syndromes.
Methods
We searched five electronic databases, hand-searched reference lists of included studies and contacted content experts to identify articles for review. We included prospective cohort studies that validated the TIMI risk score in emergency department patients. We performed a meta-regression to determine whether a linear relation exists between TIMI risk score and the cumulative incidence of cardiac events.
Results
We included 10 prospective cohort studies (with a total of 17 265 patients) in our systematic review. Data were available for meta-analysis in 8 of the 10 studies. Of patients with a score of zero, 1.8% had a cardiac event within 30 days (sensitivity 97.2%, 95% CI 96.4–97.8; specificity 25.0%, 95% CI 24.3–25.7; positive likelihood ratio 1.30, 95% CI 1.28–1.31; negative likelihood ratio 0.11, 95% CI 0.09–0.15). Meta-regression analysis revealed a strong linear relation between TIMI risk score (p < 0.001) and the cumulative incidence of cardiac events.
Interpretation
Although the TIMI risk score is an effective risk stratification tool for patients in the emergency department with potential acute coronary syndromes, it should not be used as the sole means of determining patient disposition.
doi:10.1503/cmaj.092119
PMCID: PMC2900327  PMID: 20530163
4.  Corticosteroid Administration and Outcome of Adolescents and Adults With Acute Bacterial Meningitis: A Meta-analysis 
Mayo Clinic Proceedings  2009;84(5):403-409.
OBJECTIVE: To systematically assess the effect of the adjunctive administration of corticosteroids in the treatment of acute bacterial meningitis.
METHODS: We performed a systematic review and meta-analysis by searching several databases for reports (published from January 1966 through February 2008) of placebo-controlled randomized trials of corticosteroid use in the treatment of adolescents and adults with acute bacterial meningitis. We used random-effects models. Sources of heterogeneity were explored by preplanned subgroup analyses.
RESULTS: The 4 eligible trials (published between 1999 and 2007) were of high methodological quality and included 1261 adult patients. Overall, the short-term mortality rate associated with corticosteroid administration was not significantly lower than that associated with placebo (relative risk [RR], 0.81; 95% confidence interval [CI], 0.54-1.20; I2=54%). A significant interaction was found between the effect of corticosteroids and the income status of the country (P=.02) and the prevalence of infection with human immunodeficiency virus (HIV) among study populations (P=.03). The administration of corticosteroids resulted in a lower short-term mortality rate than did the administration of placebo in high-income countries (pooled RR, 0.5; 95% CI, 0.27-0.92; I2=0%) and in the studies with a low prevalence of infection with HIV (RR, 0.66; 95% CI, 0.44-0.99; I2=0%). In studies from high-income countries, the number needed to treat with corticosteriods to prevent 1 death and 1 neurologic sequela was 12.5 (95% CI, 7.1-100.0) and 11.0 (95% CI, 5.6-100.0), respectively.
CONCLUSION: Our meta-analysis suggests that the adjunctive administration of corticosteroids is beneficial in the treatment of adolescents and adults with bacterial meningitis in patient populations similar to those seen in high-income countries and in areas with a low prevalence of HIV infection.
This meta-analysis of published randomized, placebo-controlled trials suggests that the adjunctive administration of corticosteroids is beneficial in the treatment of adolescents and adults with acute bacterial meningitis in patient populations similar to those seen in high-income countries and in areas with a low prevalence of human immunodeficiency virus infection.
PMCID: PMC2676122  PMID: 19411436
6.  The Association between Histamine 2 Receptor Antagonist Use and Clostridium difficile Infection: A Systematic Review and Meta-analysis 
PLoS ONE  2013;8(3):e56498.
Background
Clostridium difficile infection (CDI) is a major health problem. Epidemiological evidence suggests that there is an association between acid suppression therapy and development of CDI.
Purpose
We sought to systematically review the literature that examined the association between histamine 2 receptor antagonists (H2RAs) and CDI.
Data source
We searched Medline, Current Contents, Embase, ISI Web of Science and Elsevier Scopus from 1990 to 2012 for all analytical studies that examined the association between H2RAs and CDI.
Study selection
Two authors independently reviewed the studies for eligibility.
Data extraction
Data about studies characteristics, adjusted effect estimates and quality were extracted.
Data synthesis
Thirty-five observations from 33 eligible studies that included 201834 participants were analyzed. Studies were performed in 6 countries and nine of them were multicenter. Most studies did not specify the type or duration of H2RAs therapy. The pooled effect estimate was 1.44, 95% CI (1.22–1.7), I2 = 70.5%. This association was consistent across different subgroups (by study design and country) and there was no evidence of publication bias. The pooled effect estimate for high quality studies was 1.39 (1.15–1.68), I2 = 72.3%. Meta-regression analysis of 10 study-level variables did not identify sources of heterogeneity. In a speculative analysis, the number needed to harm (NNH) with H2RAs at 14 days after hospital admission in patients receiving antibiotics or not was 58, 95% CI (37, 115) and 425, 95% CI (267, 848), respectively. For the general population, the NNH at 1 year was 4549, 95% CI (2860, 9097).
Conclusion
In this rigorous systematic review and meta-analysis, we observed an association between H2RAs and CDI. The absolute risk of CDI associated with H2RAs is highest in hospitalized patients receiving antibiotics.
doi:10.1371/journal.pone.0056498
PMCID: PMC3587620  PMID: 23469173
7.  Effects of cyclophosphamide on pulmonary function in patients with scleroderma and interstitial lung disease: a systematic review and meta-analysis of randomized controlled trials and observational prospective cohort studies 
Arthritis Research & Therapy  2008;10(5):R124.
Introduction
The purpose of the present study was to systematically review the effect of cyclophosphamide treatment on pulmonary function in patients with systemic sclerosis and interstitial lung disease.
Methods
The primary outcomes were the mean change in forced vital capacity and in diffusing capacity for carbon monoxide after 12 months of therapy in patients treated with cyclophosphamide.
Results
Three randomized clinical trials and six prospective observational studies were included for analysis. In the pooled analysis, the forced vital capacity and the diffusing capacity for carbon monoxide predicted values after 12 months of therapy were essentially unchanged, with mean changes of 2.83% (95% confidence interval = 0.35 to 5.31) and 4.56% (95% confidence interval = -0.21 to 9.33), respectively.
Conclusions
Cyclophosphamide treatment in patients with systemic sclerosis-related interstitial lung disease does not result in clinically significant improvement of pulmonary function.
doi:10.1186/ar2534
PMCID: PMC2592814  PMID: 18937831
8.  How Reliable Are Assessments of Clinical Teaching? 
BACKGROUND
Learner feedback is the primary method for evaluating clinical faculty, despite few existing standards for measuring learner assessments.
OBJECTIVE
To review the published literature on instruments for evaluating clinical teachers and to summarize themes that will aid in developing universally appealing tools.
DESIGN
Searching 5 electronic databases revealed over 330 articles. Excluded were reviews, editorials, and qualitative studies. Twenty-one articles describing instruments designed for evaluating clinical faculty by learners were found. Three investigators studied these papers and tabulated characteristics of the learning environments and validation methods. Salient themes among the evaluation studies were determined.
MAIN RESULTS
Many studies combined evaluations from both outpatient and inpatient settings and some authors combined evaluations from different learner levels. Wide ranges in numbers of teachers, evaluators, evaluations, and scale items were observed. The most frequently encountered statistical methods were factor analysis and determining internal consistency reliability with Cronbach's α. Less common methods were the use of test-retest reliability, interrater reliability, and convergent validity between validated instruments. Fourteen domains of teaching were identified and the most frequently studied domains were interpersonal and clinical-teaching skills.
CONCLUSIONS
Characteristics of teacher evaluations vary between educational settings and between different learner levels, indicating that future studies should utilize more narrowly defined study populations. A variety of validation methods including temporal stability, interrater reliability, and convergent validity should be considered. Finally, existing data support the validation of instruments comprised solely of interpersonal and clinical-teaching domains.
doi:10.1111/j.1525-1497.2004.40066.x
PMCID: PMC1492515  PMID: 15333063
validity; evaluation studies; medical faculty
9.  The Role of Statins in Prevention and Treatment of Community Acquired Pneumonia: A Systematic Review and Meta-Analysis 
PLoS ONE  2013;8(1):e52929.
Background
Emerging epidemiological evidence suggests that statins may reduce the risk of community-acquired pneumonia (CAP) and its complications.
Purpose
Performed a systematic review to address the role of statins in the prevention or treatment of CAP.
Data Source
Ovid MEDLINE, Cochrane, EMBASE, ISI Web of Science, and Scopus from inception through December 2011 were searched for randomized clinical trials, cohort and case-control studies.
Study Selection
Two authors independently reviewed studies that examined the role of statins in CAP.
Data Extraction
Data about study characteristics, adjusted effect-estimates and quality characteristics was extracted.
Data Synthesis
Eighteen studies corresponding to 21 effect-estimates (eight and 13 of which addressed the preventive and therapeutic roles of statins, respectively) were included. All studies were of good methodological quality. Random-effects meta-analyses of adjusted effect-estimates were used. Statins were associated with a lower risk of CAP, 0.84 (95% CI, 0.74–0.95), I2 = 90.5% and a lower short-term mortality in patients with CAP, 0.68 (95% CI, 0.59–0.78), I2 = 75.7%. Meta-regression did not identify sources of heterogeneity. A funnel plot suggested publication bias in the treatment group, which was adjusted by a novel regression method with a resultant effect-estimate of 0.85 (95% CI, 0.77–0.93). Sensitivity analyses using the rule-out approach showed that it is unlikely that the results were due to an unmeasured confounder.
Conclusions
Our meta-analysis reveals a beneficial role of statins for the risk of development and mortality associated with CAP. However, the results constitute very low quality evidence as per the GRADE framework due to observational study design, heterogeneity and publication bias.
doi:10.1371/journal.pone.0052929
PMCID: PMC3538683  PMID: 23349694
11.  Association between Proton Pump Inhibitor Therapy and Clostridium difficile Infection: A Contemporary Systematic Review and Meta-Analysis 
PLoS ONE  2012;7(12):e50836.
Introduction
Emerging epidemiological evidence suggests that proton pump inhibitor (PPI) acid-suppression therapy is associated with an increased risk of Clostridium difficile infection (CDI).
Methods
Ovid MEDLINE, EMBASE, ISI Web of Science, and Scopus were searched from 1990 to January 2012 for analytical studies that reported an adjusted effect estimate of the association between PPI use and CDI. We performed random-effect meta-analyses. We used the GRADE framework to interpret the findings.
Results
We identified 47 eligible citations (37 case-control and 14 cohort studies) with corresponding 51 effect estimates. The pooled OR was 1.65, 95% CI (1.47, 1.85), I2 = 89.9%, with evidence of publication bias suggested by a contour funnel plot. A novel regression based method was used to adjust for publication bias and resulted in an adjusted pooled OR of 1.51 (95% CI, 1.26–1.83). In a speculative analysis that assumes that this association is based on causality, and based on published baseline CDI incidence, the risk of CDI would be very low in the general population taking PPIs with an estimated NNH of 3925 at 1 year.
Conclusions
In this rigorously conducted systemic review and meta-analysis, we found very low quality evidence (GRADE class) for an association between PPI use and CDI that does not support a cause-effect relationship.
doi:10.1371/journal.pone.0050836
PMCID: PMC3517572  PMID: 23236397
12.  Treatment of hyperprolactinemia: a systematic review and meta-analysis 
Systematic Reviews  2012;1:33.
Background
Hyperprolactinemia is a common endocrine disorder that can be associated with significant morbidity. We conducted a systematic review and meta-analyses of outcomes of hyperprolactinemic patients, including microadenomas and macroadenomas, to provide evidence-based recommendations for practitioners. Through this review, we aimed to compare efficacy and adverse effects of medications, surgery and radiotherapy in the treatment of hyperprolactinemia.
Methods
We searched electronic databases, reviewed bibliographies of included articles, and contacted experts in the field. Eligible studies provided longitudinal follow-up of patients with hyperprolactinemia and evaluated outcomes of interest. We collected descriptive, quality and outcome data (tumor growth, visual field defects, infertility, sexual dysfunction, amenorrhea/oligomenorrhea and prolactin levels).
Results
After review, 8 randomized and 178 nonrandomized studies (over 3,000 patients) met inclusion criteria. Compared to no treatment, dopamine agonists significantly reduced prolactin level (weighted mean difference, -45; 95% confidence interval, -77 to −11) and the likelihood of persistent hyperprolactinemia (relative risk, 0.90; 95% confidence interval, 0.81 to 0.99). Cabergoline was more effective than bromocriptine in reducing persistent hyperprolactinemia, amenorrhea/oligomenorrhea, and galactorrhea. A large body of noncomparative literature showed dopamine agonists improved other patient-important outcomes. Low-to-moderate quality evidence supports improved outcomes with surgery and radiotherapy compared to no treatment in patients who were resistant to or intolerant of dopamine agonists.
Conclusion
Our results provide evidence to support the use of dopamine agonists in reducing prolactin levels and persistent hyperprolactinemia, with cabergoline proving more efficacious than bromocriptine. Radiotherapy and surgery are useful in patients with resistance or intolerance to dopamine agonists.
doi:10.1186/2046-4053-1-33
PMCID: PMC3483691  PMID: 22828169
Treatment; Hyperprolactinemia; Macroprolactinoma; Microprolactinoma
13.  Efficacy of Continuous Glucose Monitoring in Improving Glycemic Control and Reducing Hypoglycemia: A Systematic Review and Meta-Analysis of Randomized Trials 
Objective
We conducted a systematic review and meta-analysis to assess the efficacy of continuous glucose monitoring (CGM) in improving glycemic control and reducing hypoglycemia compared to self-monitored blood glucose (SMBG).
Methods
We searched MEDLINE, EMBASE, Cochrane Central, Web of Science, and Scopus for randomized trials of adults and children with type 1 or type 2 diabetes mellitus (T1DM or T2DM). Pairs of reviewers independently selected studies, assessed methodological quality, and extracted data. Meta-analytic estimates of treatment effects were generated using a random-effects model.
Results
Nineteen trials were eligible and provided data for meta-analysis. Overall, CGM was associated with a significant reduction in mean hemoglobin A1c [HbA1c; weighted mean difference (WMD) of -0.27% (95% confidence interval [CI] -0.44 to -0.10)]. This was true for adults with T1DM as well as T2DM [WMD -0.50% (95% CI -0.69 to -0.30) and -0.70 (95% CI, -1.14 to -0.27), respectively]. No significant effect was noted in children and adolescents. There was no significant difference in HbA1c reduction between studies of real-time versus non-realtime devices (WMD -0.22%, 95% CI, -0.59 to 0.15 versus -0.30%, 95% CI, -0.49 to -0.10; p for interaction 0.71). The quality of evidence was moderate due to imprecision, suggesting increased risk for bias. Data for the incidence of severe or nocturnal hypoglycemia were sparse and imprecise. In studies that reported patient satisfaction, users felt confident about the device and gave positive reviews.
Conclusion
Continuous glucose monitoring seems to help improve glycemic control in adults with T1DM and T2DM. The effect on hypoglycemia incidence is imprecise and unclear. Larger trials with longer follow-up are needed to assess the efficacy of CGM in reducing patient-important complications without significantly increasing the burden of care for patients with diabetes.
PMCID: PMC3192603  PMID: 21880239
biosensing techniques; blood glucose self-monitoring; diabetes mellitus
14.  The association of hypertriglyceridemia with cardiovascular events and pancreatitis: a systematic review and meta-analysis 
Background
Hypertriglyceridemia may be associated with important complications. The aim of this study is to estimate the magnitude of association and quality of supporting evidence linking hypertriglyceridemia to cardiovascular events and pancreatitis.
Methods
We conducted a systematic review of multiple electronic bibliographic databases and subsequent meta-analysis using a random effects model. Studies eligible for this review followed patients longitudinally and evaluated quantitatively the association of fasting hypertriglyceridemia with the outcomes of interest. Reviewers working independently and in duplicate reviewed studies and extracted data.
Results
35 studies provided data sufficient for meta-analysis. The quality of these observational studies was moderate to low with fair level of multivariable adjustments and adequate exposure and outcome ascertainment. Fasting hypertriglyceridemia was significantly associated with cardiovascular death (odds ratios (OR) 1.80; 95% confidence interval (CI) 1.31-2.49), cardiovascular events (OR, 1.37; 95% CI, 1.23-1.53), myocardial infarction (OR, 1.31; 95% CI, 1.15-1.49), and pancreatitis (OR, 3.96; 95% CI, 1.27-12.34, in one study only). The association with all-cause mortality was not statistically significant.
Conclusions
The current evidence suggests that fasting hypertriglyceridemia is associated with increased risk of cardiovascular death, MI, cardiovascular events, and possibly acute pancreatitis.
Précis: hypertriglyceridemia is associated with increased risk of cardiovascular death, MI, cardiovascular events, and possibly acute pancreatitis
doi:10.1186/1472-6823-12-2
PMCID: PMC3342117  PMID: 22463676
Hypertriglyceridemia; Cardiovascular disease; Pancreatitis; Systematic reviews and meta-analysis
15.  Factors Influencing Cancer Risk Perception in High Risk Populations: A Systematic Review 
Background
Patients at higher than average risk of heritable cancer may process risk information differently than the general population. However, little is known about clinical, demographic, or psychosocial predictors that may impact risk perception in these groups. The objective of this study was to characterize factors associated with perceived risk of developing cancer in groups at high risk for cancer based on genetics or family history.
Methods
We searched Ovid MEDLINE, Ovid Embase, Ovid PsycInfo, and Scopus from inception through April 2009 for English-language, original investigations in humans using core concepts of "risk" and "cancer." We abstracted key information and then further restricted articles dealing with perceived risk of developing cancer due to inherited risk.
Results
Of 1028 titles identified, 53 articles met our criteria. Most (92%) used an observational design and focused on women (70%) with a family history of or contemplating genetic testing for breast cancer. Of the 53 studies, 36 focused on patients who had not had genetic testing for cancer risk, 17 included studies of patients who had undergone genetic testing for cancer risk. Family history of cancer, previous prophylactic tests and treatments, and younger age were associated with cancer risk perception. In addition, beliefs about the preventability and severity of cancer, personality factors such as "monitoring" personality, the ability to process numerical information, as well as distress/worry also were associated with cancer risk perception. Few studies addressed non-breast cancer or risk perception in specific demographic groups (e.g. elderly or minority groups) and few employed theory-driven analytic strategies to decipher interrelationships of factors.
Conclusions
Several factors influence cancer risk perception in patients at elevated risk for cancer. The science of characterizing and improving risk perception in cancer for high risk groups, although evolving, is still relatively undeveloped in several key topic areas including cancers other than breast and in specific populations. Future rigorous risk perception research using experimental designs and focused on cancers other than breast would advance the field.
doi:10.1186/1897-4287-9-2
PMCID: PMC3118965  PMID: 21595959

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