Chapter 5: Understanding Evidence-Based Practice

Introduction

Evidence-based practice (EBP) is about clinical decision-making—how we find and use information and how we integrate knowledge, experience, and judgment to address clinical problems. EBP requires a mindset that values evidence as an important component of quality care and a skill set in searching the literature, critical appraisal, synthesis, and reasoning to determine the applicability of evidence to current issues. The ultimate goal is to create a culture of inquiry and rigorous evaluation that provides a basis for balancing quality with the uncertainty that is found in practice—all in the effort to improve patient care.

The purpose of this chapter is to clarify how evidence contributes to clinical decision-making, describe the process of EBP and the types of evidence that are meaningful, and discuss the barriers that often limit successful implementation. This discussion will continue throughout the text in relation to specific elements of research design and analysis.

Why Is Evidence-Based Practice Important?

In a landmark 2001 report, Crossing the Quality Chasm,¹ the Institute of Medicine (IOM) documented a significant gap between what we know and what we do, between the care people should receive and the care they actually receive, between published evidence and healthcare practice. The IOM estimates that one-third of healthcare spending is for therapies that do not improve health.² Another review suggests that 50% of healthcare practices are of unknown effectiveness and 15% are potentially harmful or unlikely to be beneficial.^3,4 Consider, for example, the change in recommendations for infant sleep position, for many years preferred on the stomach, to reduce the possibility of spitting up and choking. In 1992, this recommendation was changed to sleeping on the back, which improved breathing and drastically changed the incidence of sudden infant death syndrome (SIDS).⁵

Clinicians tackle questions every day in practice, constantly faced with the task of interpreting results of diagnostic tests, determining the efficacy of therapeutic and preventive regimens, the potential harm associated with different treatments, the course and prognosis of specific disorders, costs of tests or interventions, and whether guidelines are sound. Despite having these questions, however, and even with an emphasis on EBP across healthcare, practitioners in most professional disciplines do not seek answers or they express a lack of confidence in evidence, with a higher value placed on experience, collegial advice, or anecdotal evidence than on research to support clinical decisions.^6,7

From an evidence-based standpoint, research has continued to document escalating healthcare costs, disparities in access to healthcare, and unwarranted variations in accepted practice—with geography, ethnicity, socioeconomic status, and clinical setting often cited as major determinants.^8–11 Addressing these issues requires understanding how evidence informs our choices to support quality care.