Image from the Duke University EBP guide

Evidence-based medicine (EBM) is the integration of best research evidence with clinical expertise and patient values.

• by best research evidence we mean clinically relevant research, often from the basic sciences of medicine, but especially from patient centered clinical research into the accuracy and precision of diagnostic tests (including the clinical examination), the power of prognostic markers, and the efficacy and safety of therapeutic, rehabilitative, and preventive regimens. New evidence from clinical research both invalidates previously accepted diagnostic tests and treatments and replaces them with new ones that are more powerful, more accurate, more efficacious, and safer.
• by clinical expertise we mean the ability to use our clinical skills and past experience to rapidly identify each patient's unique health state and diagnosis, their individual risks and benefits of potential interventions, and their personal values and expectations.
• by patient values we mean the unique preferences, concerns and expectations each patient brings to a clinical encounter and which must be integrated into clinical decisions if they are to serve the patient.

Straus, S. E., Glasziou, P., Richardson, W. S., & Haynes, R. B. (2019). Evidence-based medicine: How to practice and teach EBM.

Image from the Duke University EBP guide 

The patient is at the center of evidence-based medicine decision-making. 

1. Assess the patient with a thorough clinical evaluation to gather all the pertinent data about the patient(s) or population(s)
2. Ask  patient-oriented, relevant, answerable questions about the health status and context of patients or populations 
3. Acquire the best available evidence to answer the question 
4. Appraise the evidence critically for validity and applicability to the problem at hand
5. Apply the evidence by engaging in collaborative health decision-making with the patient(s) or population(s) 

Evidence cycle description from the Duke Program on Teaching Evidence-Based Practice 

You can learn more and access resources relating to EBM from the Evidence Based Medicine Research Guide.

Meta Analysis – a type of systematic review that combines the results using accepted statistical methodology as if they were from one large study. 

Systematic Review – focuses on a specific clinical question and includes an extensive/explicit review of the literature to identify studies with sound methodology. Data extracted from the selected studies are combined (if possible), compared, and assessed. Conclusions are made based on results and/or the presence or absence of supporting evidence. 

Randomized Controlled Trial (RCT) – a prospective, analytical, experimental study using primary data generated in the clinical environment. Individuals similar at the beginning are randomly allocated to two or more treatment groups and the outcomes the groups are compared after sufficient follow-up time.

A study that shows the efficacy of a diagnostic test is a prospective, blind comparison to a gold standard. This is a controlled trial that looks at individual with varying degrees of an illness and applies two diagnostic tests to each individual: the test under investigation and the “gold standard” test.   

Cohort (Prospective, Incidence, Longitudinal, Follow-up) Study – a prospective, analytical, observational study of a population (or cohort) who had, have or will have a specific exposure or treatment of interest . This outcome of this cohort is compared to the general population or another group that has not been effected by the exposure or treatment of interest. Cohort studies are susceptible to bias because the two groups may differ in ways beyond the variable in the study. 

Case-Control Study – a retrospective, analytical, observational study often based on secondary data in which individuals with a condition or outcome are compared with individuals who do not, but have the same risk factor.  Often using medical records or patient recall, researches look back in time to identify possible exposures. y useful for rare conditions or for risk factors with long induction . However, due to the potential for many forms of bias in this study type, case control studies provide relatively weak empirical evidence even when properly executed. 

Case Series or Case Report – anecdotal evidence. A description of a single case (or several cases), typically describing the manifestations, clinical course, and prognosis of that case. Due to the wide range of natural biologic variability in these aspects, a single case report provides little empirical evidence to the clinician. They do describe how others diagnosed and treated the condition and what the clinical outcome was.