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  • How do the levels of evidence compare, ie. How do you utilize information from case reports vs. randomized controlled trials (RCTs)?

  • What are meta-analyses, and how can they help you with decision-making?

  • How do you interpret p values, confidence intervals (CIs), the number needed to treat, and positive/negative predictive values?

  • How does one start contributing to the evidence and get started on research?

CASE 10-1

25yo G2P1001 at 36wk EGA who presents to clinic for routine prenatal exam. Pregnancy has been uncomplicated. Bedside ultrasound shows breech presentation. You discuss with the patient about the option for external cephalic version (ECV) and its risks. The patient asks if there is anything you can do to improve the chance of success.

You have participated in several ECV procedures in which different attendings used terbutaline, nifedipine, and sublingual nitroglycerine spray prior to ECV. You want to choose a method that provides the strongest evidence of benefit for this patient.

How would you find this information?

Evidence-based medicine (EBM) is considered the gold standard of optimal care by healthcare professionals worldwide, with significant and conscious focus at academic centers. Although its philosophy dated back to the 1800s, the term was coined in 1990 by Dr. Gordon Guyatt to describe his new residency program curriculum based on the teaching and practices of his mentor, Dr. David Sackett. This term later was introduced widely to academic medicine cultures in a 1991 American College of Physicians (ACP) Journal Club editorial that launches Dr. David Sackett's title as the father of EBM.1,2

Sackett defines EBM as “the integration of best research evidence with clinical expertise and patient values” including “patient's preferences, concerns and expectations.”3 It is the intentional and rigorous effort to make clinical decisions based on the highest level of evidence acquired from the most exhaustive search, rather than relying on personal experience alone. Its process encourages practice changes as more evidence emerges, so that clinical decisions would continually evolve. EBM has changed the standard of practice of numerous medical therapies over the decades. One well-known example is the discontinuation of diethylstilbestrol (DES) during pregnancy as evidence of harm accumulated over time.


In formulating a research question, key parameters are Patient/population and Problem, Intervention, Comparison, and Outcome (PICO)4 (see Table 10-1). This guideline helps the conscientious clinician target the literature search specific to the patient currently on the exam table.

TABLE 10-1PICO Method to Formulate a Clinical Question

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