Health care professionals are increasingly required to base clinical decisions on the best available evidence. Evidence-based medicine (EBM) is a systematic approach to clinical problem solving which allows the integration of the best available research evidence with clinical expertise and patient values.To get there, the 5 step EBM model needs to be introduced.<ol><li>Creating an answerable clinical questions.</li><li>Search for evidence.</li><li>Critical Appraisal of evidence.</li><li>Applying the evidence.</li><li>Evaluating the performance.</li></ol>

1] Principles of evidence based medicine

The concept of evidence-based medicine (EBM), defined as the ‘‘integration of best research evidence with clinical expertise and patient values’’The practice of it requires life long, self-directed learning where patient care creates the need for important information about clinical and other healthcare issues.Healthcare and science is ever-changing, so staying current is imperative.This is made easier by utilising the tools of EBM; such as finding the relevant evidence, critically appraising it and using it in daily clinical practice.

2] What is evidence-based medicine?

To Improve quality care through the identification and promotion of practices that work, and the elimination of those that are ineffective or harmful.EBM demands that the effectiveness of clinical interventions, the accuracy of diagnostic tests, and the power of prognostic markers should be scrutinised and their usefulness proven.Clinicians should be open to try new scientifically proven methods and discard those that aren't. It's important that clinicians develop key EBM skills including the ability to find, critically appraise, and incorporate sound scientific evidence in their own practice.

3] Why evidence-based medicine

The practice of EBM should start with a well formulated clinical question.A good question should be clear, directly focused on the problem and answerable by medical literature research. A good clinical question has 3-4 components:<ul><li>Patient or problem</li><li>Intervention, test or exposure of interest</li><li>Comparison interventions (if applicable)</li><li>Outcome(s)</li></ul>Question should then be made using the PICO (Patient, Intervention, Comparison, Outcome) or PIO (Patient, Intervention, Outcome) format .

4] EMB model 1: Creating answerable clinical questions.

A 4 month old baby is admitted with viral bronchiolitis. The baby's symptoms worsen and you wonder if corticosteroids might help the child improve and reduce the length of hospital stay.The key components of your clinical question would be:Patient: 4 month old baby with viral bronchiolitis.Intervention: corticosteroids.Comparison: no corticosteroids.Outcomes: clinical score, length of stay.Clinical question may be formulated as follows:In a 4 month old baby with viral bronchiolitis, does the administration of corticosteroids improve clinical score and reduce length of hospital stay, or not?

5] PICO/PIO Example:

The next step is to seek relevant evidence that will help you answer the question.Sources are:<ol><li>Traditional methods (textbooks, journals).</li><li>Ask an expert. (answer quality will vary)</li><li>Summarised clinical evidence (<a href="www.bestbets.org">BestBets</a>).</li><li>Electronic bibliographic databases(<a href="https://www.cochranelibrary.com/">Cochrane</a> Library databases, <a href="https://pubmed.ncbi.nlm.nih.gov/">PUBMED</a>, <a href="https://www.nlm.nih.gov/">MEDLINE</a>, <a href="https://www.embase.com/landing?status=grey">EMBASE</a>, and <a href="https://www.ebsco.com/products/research-databases/cinahl-complete">CINAHL</a>).</li></ol> To find relevant articles fast:<ul><li>Use Boolean operators "AND" and "OR"</li><li>Example:</li></ul><ol><li>Viral bronchiolitis</li><li>Corticosteroids OR steroids OR glucocorticoids OR prednisolone OR dexamethasone</li><li>Clinical score OR hospital stay</li><li>(1) AND (2) AND (3).</li></ol>

6] EBM model 2: Finding the evidence.

After obtaining relevant articles on a subject, the next step is to appraise the evidence for its validity and clinical usefulness.Research evidence may be appraised with regard to three main areas: <ol><li>Validity</li><li>Importance</li><li>Applicability to the patient or patients of interest.</li></ol>Critical appraisal provides simple, structured methods for assessing research evidence in all three areas. Appraisal skills may be learnt within small tutorials, workshops, interactive lectures, and at the bedside.Tools for appraising research articles are available. Like the Critical Appraisal Skills Programme (<a href="https://casp-uk.net/">CASP</a>).

7] EBM model 3: Critical appraisal.

After critically appraising the evidence, we then decide whether that evidence can be applied to our individual patient or population, taking into account the patient’s own personal values and circumstances.Both efficacy and risks should be fully discussed with the patient or parents, or both, to allow them to make an informed decision.This approach is consistent with the EBM principle: the integration of good evidence with clinical expertise and patient values.This decision should also take into account the feasibility and availability of the treatment.

8] EBM model 4: Applying the evidence.

As we incorporate EBM into routine clinical practice, we need to evaluate our approach at frequent intervals and to decide whether we need to improve on any of the four steps discussed above.We need to ask whether we are formulating answerable questions, finding good evidence quickly, effectively appraising the evidence, and integrating clinical expertise and patient’s values with the evidence in a way that leads to a rational, acceptable management strategy.Formal auditing of performance may be needed to show whether the EBM approach is improving patient care.

Principles of evidence based medicine: Summary