Evidence-based medicine and problem based learning a critical re-evaluation.

Evidence-based medicine (EBM) has been the subject of controversy since it was introduced in 1992. However, it has yet to be critically examined as an alternative paradigm for medical education, which is how it was proposed. This commentary examines EBM on the terms on which it was originally advanced and within the context that gave rise to it, the problem-based learning (PBL) environment at McMaster University in the 1970s and 80s. The EBM educational prescription is revealed to be aligned with the information processing psychology (IPP) model of learning through acquisition of general problem solving skills that characterized the early McMaster version of PBL. The IPP model has been identified in the literature as discordant with an alternative, constructivist, model that emerged at Maastricht University in the Netherlands over the subsequent period. Strengths and weaknesses of EBM are identified from the standpoint of the underlying cognitive theories. Principles are proposed with which to guide an educationally viable approach to learning and teaching the valuable skills included within the original EBM formula.

How to read a systematic review and meta-analysis and apply the results to patient care: users' guides to the medical literature.

Clinical decisions should be based on the totality of the best evidence and not the results of individual studies. When clinicians apply the results of a systematic review or meta-analysis to patient care, they should start by evaluating the credibility of the methods of the systematic review, ie, the extent to which these methods have likely protected against misleading results. Credibility depends on whether the review addressed a sensible clinical question; included an exhaustive literature search; demonstrated reproducibility of the selection and assessment of studies; and presented results in a useful manner. For reviews that are sufficiently credible, clinicians must decide on the degree of confidence in the estimates that the evidence warrants (quality of evidence). Confidence depends on the risk of bias in the body of evidence; the precision and consistency of the results; whether the results directly apply to the patient of interest; and the likelihood of reporting bias. Shared decision making requires understanding of the estimates of magnitude of beneficial and harmful effects, and confidence in those estimates.

Revelation of mindlines in the setting of crisis.

During the devastating early months of the unfolding COVID-19 pandemic in New York, healthcare systems and clinicians dynamically adapted to drastically changing everyday practice despite having little guidance from formal research evidence in the face of a novel virus. Through new, silo-breaking networks of communication, clinical teams transformed and synthesized provisional recommendations, rudimentary published research findings and numerous other sources of knowledge to address the immediate patient care needs they faced during the pandemic surge. These experiences illustrated underlying social processes that are always at play as clinicians integrate information from various sources, including research and published guidelines, with their own tacit knowledge to develop shared yet personal approaches to practice. In this article, we provide a narrative account of personal experience during the COVID-19 surge. We draw on the concept of mindlines as developed by Gabbay and Le May as a conceptual framework for interpreting that experience from the standpoint of how early information from research and guidelines was drawn on and transformed in the course of day-to-day struggle with the crisis in New York City emergency rooms. Finally, briefly referencing the challenges to conventional models of healthcare knowledge creation and translation through research and guideline production posed by COVID-19 crisis, we offer a provisional perspective on current and future developments.

Dual process models of clinical reasoning: The central role of knowledge in diagnostic expertise.

RATIONALE: Research on diagnostic reasoning has been conducted for fifty years or more. There is growing consensus that there are two distinct processes involved in human diagnostic reasoning: System 1, a rapid retrieval of possible diagnostic hypotheses, largely automatic and based to a large part on experiential knowledge, and System 2, a slower, analytical, conscious application of formal knowledge to arrive at a diagnostic conclusion. However, within this broad framework, controversy and disagreement abound. In particular, many authors have suggested that the root cause of diagnostic errors is cognitive biases originating in System 1 and propose that educating learners about the types of cognitive biases and their impact on diagnosis would have a major influence on error reduction. AIMS AND OBJECTIVES: In the present paper, we take issue with these claims. METHOD: We reviewed the literature to examine the extent to which this theoretical model is supported by the evidence. RESULTS: We show that evidence derived from fundamental research in human cognition and studies in clinical medicine challenges the basic assumptions of this theory-that errors arise in System 1 processing as a consequence of cognitive biases, and are corrected by slow, deliberative analytical processing. We claim that, to the contrary, errors derive from both System 1 and System 2 reasoning, that they arise from lack of access to the appropriate knowledge, not from errors of processing, and that the two processes are not essential to the process of diagnostic reasoning. CONCLUSIONS: The two processing modes are better understood as a consequence of the nature of the knowledge retrieved, not as independent processes.

Eating a larger number of high-salt foods is not associated with short-term risk of acute decompensation in patients with chronic heart failure.

BACKGROUND: Risk factors for exacerbation of congestive heart failure have not been consistently validated. OBJECTIVE: Our objective was to examine the role of short-term dietary sodium intake in acute decompensated heart failure. METHODS: Patients with chronic congestive heart failure presenting to the Emergency Department for either acute decompensated heart failure (cases) or for other reasons (controls) were included in a case-control study. Cases and controls were compared with respect to age, smoking, recent sodium intake, medication nonadherence, coronary artery disease, and hypertension. A food frequency questionnaire was utilized to estimate recent sodium intake, defined as the number of food types consumed in the previous 3 days from the 12 highest-sodium food categories. RESULTS: There were 182 patients enrolled. One patient was excluded due to uncertainty about the primary diagnosis. When adjusted for age, smoking, medication nonadherence, coronary artery disease, and hypertension, acute decompensated heart failure was not associated with short-term dietary sodium intake. The odds ratio for acute decompensated heart failure for each increase in the number of high-sodium food types consumed was 1.1 (95% confidence interval 0.9-1.3; p = 0.3). Acute decompensated heart failure was associated with medication nonadherence, with an odds ratio for decompensation of 2.5 (95% confidence interval 1.2-5.1; p = 0.01). CONCLUSIONS: Patients with chronic congestive heart failure who presented to the Emergency Department with acute decompensated heart failure were no more likely to report consuming a greater number of high-sodium foods in the 3 days before than were patients with chronic congestive heart failure who presented with unrelated symptoms. On the other hand, those who presented with acute decompensated heart failure were significantly more likely to report nonadherence with medications.

On crowns, caravans and windmills: Commentary on an essay by Turcotte P., et al.

Patient-oriented research (POR) is a trend that has emerged over several decades and is particularly prominent in Canada, the United States and the United Kingdom. It involves patient and other stakeholder participation in the planning, conduct and dissemination of biomedical and health services research and it can be seen as a form of public participation and engagement in activities that affect the lives and well-being of communities. Criticisms of POR revolve around its susceptibility to tokenistic treatment of patient participants and paternalistic dominance of the research agenda by professional researchers, academics and clinicians. This commentary addresses one such critique by situating the POR agenda within the challenges and dilemmas faced by the health-related research enterprise over the past 30 years. It will explore the interface between POR, community activism and community-based participatory research. The contextual importance of the COVID-19 pandemic experience is stressed. The commentary will particularly focus on the US-based Patient Centred Outcomes Research Institute, its origins within a movement to enhance emphasis on publicly funded comparative effectiveness research, and its more recent evolution in the direction of community empowerment in POR.

Validating the acute heart failure index for patients presenting to the emergency department with decompensated heart failure.

BACKGROUND: The acute heart failure index (AHFI) is a previously derived prediction rule to identify patients presenting to emergency departments (ED) with decompensated heart failure (DHF) at low risk of early life-threatening events. STUDY OBJECTIVES: To validate the AHFI prospectively. METHODS: Using a prospective cohort study, adult patients presenting to an urban university hospital ED with DHF were included. Data on 21 variables were gathered to calculate the AHFI. Primary endpoints included inpatient death and non-fatal serious outcomes (myocardial infarction, ventricular fibrillation, cardiogenic shock, cardiac arrest, intubation, or cardiac reperfusion). Secondary endpoints included death from any cause or readmission for heart failure within 30 days. Primary and secondary endpoint rates were calculated with 95% CI for the low and higher-risk subgroups. RESULTS: 259 patients were enrolled. 245/259 (95%) were admitted. 60/259 (23%) met low-risk criteria, of whom 1/60 (1.7%, CI 0.04 to 8.9) was discharged after sustaining pulseless electrical activity arrest. The comparable primary outcome rate in the derivation study was 1.4% (CI 1.1 to 1.7). 17/199 (8.5%, CI 5.1 to 13.3) higher-risk patients experienced an endpoint, compared with 13.3% (CI 12.9 to 13.7) in the derivation cohort. One low-risk patient (1.7%, CI 0.04 to 8.9) died within 30 days, and five (8.3%, CI 2.8 to 18.4) were readmitted. Corresponding rates in the derivation study were 2% and 5%, respectively. CONCLUSION: The results are consistent with those previously reported for the low-risk subgroup of the AHFI. Further research is needed to determine the impact, safety and full range of generalisability of the AHFI as an adjunct to decision making.

Depression is associated with longer emergency department length of stay in acute coronary syndrome patients.

BACKGROUND: Patient demographic characteristics have been associated with longer emergency department (ED) treatment times, but the influence of psychosocial characteristics has not been assessed. We evaluated whether depression was associated with greater ED length of stay (LOS) in non-ST elevation myocardial infarction (NSTEMI) and unstable angina (UA) patients presenting to a large metropolitan academic medical center. METHODS: We calculated ED LOS for NSTEMI or UA patients enrolled an observational cohort study by taking the difference between ED triage time in the medical record and time of transfer to an inpatient bed from standardized transfer documentation forms. Depression status was defined as current, past, or never by clinical interview and also by self-report on the Beck Depression Inventory. RESULTS: Participants were 120 NSTEMI/UA patients [mean age= 62, 36% women, 56% Hispanic, 26% Black/African American, 40% NSTEMI, mean global registry of acute cardiac events (GRACE) score= 93.9]. Mean ED LOS was 11.6 hours, SD= 8.3. A multiple linear regression model that included the above demographic and clinical variables, and time of presentation to ED, explained 11% of the variance in ED LOS, F (11, 108)= 2.35, p= .01, R2 adj.= .11. Currently depressed patients spent 5.4 more hours (95% CI= .40, 10.4 hours) in the ED on average than patients who had never been depressed. CONCLUSIONS: Currently depressed NSTEMI/UA patients are in the ED for an average of 5 hours longer than those who have never been depressed. Further research is needed to identify the reasons for this difference.

Tips for teachers of evidence-based medicine: making sense of decision analysis using a decision tree.

Decision analysis is a tool that clinicians can use to choose an option that maximizes the overall net benefit to a patient. It is an explicit, quantitative, and systematic approach to decision making under conditions of uncertainty. In this article, we present two teaching tips aimed at helping clinical learners understand the use and relevance of decision analysis. The first tip demonstrates the structure of a decision tree. With this tree, a clinician may identify the optimal choice among complicated options by calculating probabilities of events and incorporating patient valuations of possible outcomes. The second tip demonstrates how to address uncertainty regarding the estimates used in a decision tree. We field tested the tips twice with interns and senior residents. Teacher preparatory time was approximately 90 minutes. The field test utilized a board and a calculator. Two handouts were prepared. Learners identified the importance of incorporating values into the decision-making process as well as the role of uncertainty. The educational objectives appeared to be reached. These teaching tips introduce clinical learners to decision analysis in a fashion aimed to illustrate principles of clinical reasoning and how patient values can be actively incorporated into complex decision making.

Do workshops in evidence-based practice equip participants to identify and answer questions requiring consideration of clinical research? A diagnostic skill assessment.

Evidence-based practice (EBP) requires practitioners to identify and formulate questions in response to patient encounters, and to seek, select, and appraise applicable clinical research. A standardized workshop format serves as the model for training of medical educators in these skills. We developed an evaluation exercise to assess the ability to identify and solve a problem requiring the use of targeted skills and administered it to 47 North American junior faculty and residents in various specialties at the close of two short workshops in EBP. Prior to the workshop, subjects reported prior training in EBP and completed a previously validated knowledge test. Our post-workshop exercise differed from the baseline measures and required participants to spontaneously identify a suitable question in response to a simulated clinical encounter, followed by a description of a stepwise approach to answering it. They then responded to successively more explicitly prompted queries relevant to their question. We analyzed responses to identify areas of skill deficiency and potential reasons for these deficiencies. Twelve respondents (26%) initially failed to identify a suitable question in response to the clinical scenario. Ability to choose a suitable question correlated with the ability to connect an original question to an appropriate study design. Prior EBP training correlated with the pretest score but not with performance on our exercise. Overall performance correlated with ability to correctly classify their questions as pertaining to therapy, diagnosis, prognosis, or harm. We conclude that faculty and residents completing standard workshops in EBP may still lack the ability to initiate and investigate original clinical inquiries using EBP skills.

Tips for teachers of evidence-based medicine: clinical prediction rules (CPRs) and estimating pretest probability.

BACKGROUND: Clinical prediction rules (CPR) are tools that clinicians can use to predict the most likely diagnosis, prognosis, or response to treatment in a patient based on individual characteristics. CPRs attempt to standardize, simplify, and increase the accuracy of clinicians' diagnostic and prognostic assessments. The teaching tips series is designed to give teachers advice and materials they can use to attain specific educational objectives. EDUCATIONAL OBJECTIVES: In this article, we present 3 teaching tips aimed at helping clinical learners use clinical prediction rules and to more accurately assess pretest probability in every day practice. The first tip is designed to demonstrate variability in physician estimation of pretest probability. The second tip demonstrates how the estimate of pretest probability influences the interpretation of diagnostic tests and patient management. The third tip exposes learners to various examples and different types of Clinical Prediction Rules (CPR) and how to apply them in practice. PILOT TESTING: We field tested all 3 tips with 16 learners, a mix of interns and senior residents. Teacher preparatory time was approximately 2 hours. The field test utilized a board and a data projector; 3 handouts were prepared. The tips were felt to be clear and the educational objectives reached. Potential teaching pitfalls were identified. CONCLUSION: Teaching with these tips will help physicians appreciate the importance of applying evidence to their every day decisions. In 2 or 3 short teaching sessions, clinicians can also become familiar with the use of CPRs in applying evidence consistently in everyday practice.

Evidence-based emergency medicine/critically appraised topic. Evidence behind the 4-hour rule for initiation of antibiotic therapy in community-acquired pneumonia.

STUDY OBJECTIVE: US regulatory authorities mandate delivery of antibiotics within 4 hours of arrival for patients being admitted to the hospital with community-acquired pneumonia. This evidence-based emergency medicine review examines the scientific evidence pertaining to this requirement. METHODS: We searched MEDLINE, EMBASE, the Cochrane Library, other databases, and bibliographies. We selected articles allowing comparison of inpatient or 30-day mortality among patients receiving early versus delayed antibiotics. We prospectively categorized studies according to whether they were retrospective or prospective and whether they adjusted for severity with the Pneumonia Severity Index. We evaluated the precision with which the interval to initiation of antibiotic therapy was defined and the compliance of retrospective studies with standard reporting criteria for chart reviews. RESULTS: We identified 13 observational studies reporting comparative outcomes in patients receiving early versus delayed antibiotic initiation, of which 10 allowed calculation of our primary outcome. Of the 4 prospective studies, 1 allowed severity adjustment using the Pneumonia Severity Index score. Among the retrospective studies, definition of time to antibiotic therapy was frequently imprecisely defined, and compliance with standard reporting criteria for chart review was scanty in the subgroup lacking severity adjustment. Odds ratios (ORs) for mortality varied widely. One methodologically weak study reported a large benefit of early antibiotics (OR for mortality antibiotics <4 hours versus >4 hours 0.24; 95% confidence interval [CI] 0.08 to 0.71). The one study that used prospective enrollment and severity adjustment using the Pneumonia Severity Index observed a contrary result (adjusted OR for mortality, antibiotics <4 hours versus >4 hours 1.99; 95% CI 1.22 to 13.45). Results from studies reporting an 8-hour cutoff also varied in magnitude and direction of effect. CONCLUSION: Evidence from observational studies fails to confirm decreased mortality with early administration of antibiotics in stable patients with community-acquired pneumonia. Although timely administration of antibiotics to patients with confirmed community-acquired pneumonia should be encouraged, an inflated sense of priority of the 4-hour time frame is not justified by the evidence.

From MARS to MAGIC: The remarkable journey through time and space of the Grading of Recommendations Assessment, Development and Evaluation initiative.

For over 30 years, "evidence-based" clinical guidelines remained entrenched in an oversimplified, design-based, framework for rating the strength of evidence supporting clinical recommendations. The approach frequently equated the rating of evidence with that of the recommendations themselves. "Grading Recommendations Assessment, Development and Evaluation (GRADE)" has emerged as a proposed antidote to obsolete guideline methodology. GRADE sponsors and collaborators are in the process of attempting to amplify and extend the framework to encompass implementation and adaptation of guidelines, above and beyond the evaluation and rating of clinical research. Alternative schemes and models for such extensions are beginning to appear. This commentary reviews the strengths and weaknesses of GRADE with reference to other recent critiques. It considers the GRADE Working Group's "evidence-to-decision" extension of the evidence rating framework, together with proposed alternatives. It identifies pitfalls of the GRADE system's cooptation of relational processes necessary to the interpretation and uptake of recommendations that properly belong to end-users. It also identifies dangers inherent in blurring important boundaries between clinical and policy applications of guidelines. Finally, it addresses criticisms regarding the lack of a theoretical framework supporting the different facets of the GRADE approach and proposes a social constructivist orientation to clinical guideline development and use. Recommendations are offered to potential guideline developers and users regarding how to draw upon the strengths of the GRADE framework without succumbing to its pitfalls.