Network Meta-Analysis for Decision-Making

1Introduction to Evidence Synthesis

1.1 Introduction

This chapter gives a broad overview of indirect comparisons and network meta-analysis. Using a worked example, we look at what these methods are for, what they can do, the core assumptions, the kinds of output they can produce and some of the implications for decision-making. These topics are picked up and covered in more detail in later chapters.

We assume that the evidence that has been assembled for meta-analysis has been identified by a protocol-driven systematic review. Although the methods of systematic review are not covered in this book, it will become clear that the underlying assumptions of meta-analysis put certain constraints on the conduct of the systematic review. This will be discussed further, particularly in Chapter 12 on the validity of network meta-analysis. We also assume that only randomised controlled trials (RCTs) will be included in the synthesis, although we include some comments on how observational studies might be included in Chapter 9 on bias models.

We begin by discussing the purpose of indirect comparisons and network meta-analysis, which is to form the basis for coherent, evidence-based treatment decisions. We then look at some simple methods for networks involving three treatments to illustrate the concepts. Next a worked example of a larger network meta-analysis is presented to show the main properties of the method. After mentioning the assumptions made by network meta-analysis, we briefly ...