Chapter 3: Evidence-Based Medicine

INTRODUCTION

Ideal clinical care integrates a health care professional’s clinical experience, individual patient preferences and values, and current best clinical evidence. Every hospitalist has his or her own set of clinical skills and experiences and each patient has his or her own beliefs. The current best clinical evidence, however, is universal. How clinicians apply and explain this evidence to individual patients and integrate the evidence into care plans is the art of practicing evidence-based medicine (EBM). This chapter provides practical guidance on formulating questions and uses clinical examples to discuss how to efficiently and effectively use and search the medical literature.

FORMULATING QUESTIONS

Caring for patients frequently generates clinical questions. A 1985 study found that general practitioners in an office-based practice formulated two important clinical questions for every three patients examined.¹ Since there are millions of research articles in the world’s literature, finding relevant articles and assessing their quality can be time consuming. If a well-formulated clinical question is posed, the process of finding answers is easier.

There are four parts of a clinical question: the patient population, the intervention being considered, the comparison group, and the measurable outcome. Including these four parts to formulate questions will help focus literature searches.²

A 7-month-old with bronchiolitis was admitted to your service last night. In considering how best to care for her, you formulate the following:

1. Patient population (includes patient problem)—in children < 2 years with bronchiolitis

2. Intervention (diagnostic test or treatment), Prognostic factor, or Exposure—do bronchodilators

3. Comparison group—compared with placebo

4. Measurable outcome—reduce hospital length of stay?

Often, developing one critical clinical question will suffice, but a series of questions is sometimes required, especially when inpatients have complex medical problems. Clinical questions should be focused but not overly narrow, since too narrow a question may not have an answer, or may have an answer that does not apply to the individual patient.

In pediatrics, defining the patient population is important. Many hospitalists care for patients ranging in age from infants to young adults, and judgments must be made if studies that do not include your patient’s age will apply. Frequently, a study in adults has been performed and the hospitalist must decide if the study applies to a particular pediatric or adolescent patient.

Sometimes the question may not involve an intervention, and there may therefore be no comparison group to consider. For example, during morning rounds you hear about a 16-year-old female with anorexia nervosa admitted for bradycardia. You ask the question: In a female adolescent with a restrictive eating disorder and heart rate of 35, what is the risk of sudden cardiac death? This question considers the prognosis of a specific population.

The measurable outcome chosen reflects the current clinical concerns, values, and preferences of the clinician and ...