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CHAPTER OBJECTIVES

  • Identify and describe the use of formal criteria to assess the quality of randomized trials

  • Assess validity issues in randomized trials

  • Apply general criteria to evaluate methodological rigor in randomized trials

  • Evaluate common biases in randomized trials

  • Interpret and apply key findings in clinical practice

KEY TERMINOLOGY

  • Chalmers Scale

  • Composite endpoint

  • Consolidated Standards of Reporting Trials (CONSORT)

  • Construct validity

  • Jadad scale

INTRODUCTION

Randomized controlled trials (RCTs) can provide the strongest evidence when they are well-designed and conducted. Unfortunately, poor study design and methodology may produce misleading results and clinical evidence that may ultimately impact treatment decisions reaching patients.1 Several studies have evaluated the conduct and reporting of RCTs and have found that more than half of those analyzed had missing or incomplete key information regarding the methods used for allocation of patients, blinding, reporting a defined primary endpoint, and sample size calculation.2–6 This highlights the importance of critical evaluation of clinical trials by clinicians.

Treatment considerations are often based on the evidence derived from RCTs. Although these trials are designed to provide the strongest evidence for patient care, any flaw in study design and implementation can undermine the results and ultimately affect the evidence base. Clinicians should be able to identify the flaws in study design and implementation, and further evaluate the impact of flaws on the results. Patient care treatment decisions require a thorough understanding of the evidence in the context of current practice, study design and implementation, and patient-specific considerations. Chapter 4: Randomized Controlled Trials, provided details regarding the conduct of randomized trials. This chapter will identify guidelines for standard reporting of RCTs and will describe scales and checklists available for assessing randomized trials. Factors to consider when evaluating internal and external validity and other issues for critically evaluating RCTs will be outlined and applications to an example article will be included. Finally, considerations for application of RCT findings to patient care will be described and applied.

CRITERIA FOR EVALUATING AND REPORTING CLINICAL TRIALS

Standardized Reporting Requirements

Previously, biomedical journals recommended various formatting and content requirements in their guidelines for author submissions. However, in 1979, a group of medical journal editors, now known as the International Committee of Medical Journal Editors (ICMJE), published the Uniform Requirements for Manuscripts Submitted to Biomedical Journals to improve consistency of reporting.7 This document provided standard requirements for manuscript preparation in an effort to improve accuracy and clarity of reports in the medical literature. These include standard requirements for manuscript preparation and submission, statements on overlapping publications, and obligation to publish negative studies. Standards related to ethical issues with publishing (e.g. criteria for authorship) were added later. In addition to assisting authors and editors, this standardization of formatting allowed the readers to have specific expectations for the published articles. The Uniform Requirements ...

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