Network Meta-Analysis for Decision-Making

5Network Meta-Analysis Within Cost-Effectiveness Analysis

5.1 Introduction

This chapter looks at the questions that arise when a network meta-analysis is used to inform a cost-effectiveness analysis (CEA). This is a topic that has both technical and conceptual aspects.

Throughout the entire tradition of meta-analysis, going right back to the earliest papers, it has been seen as a way of pooling the relative treatment effects in trials. The focus on relative effects, it should be said, follows the huge body of classic work in epidemiological biostatistics on pooling measures of association in 2 × 2 tables (Mantel and Haenszel, 1959; Zelen, 1971; Robbins et al., 1986). The network meta-analysis models presented throughout this book belong firmly within this line of thought. Decision makers, however, have to attend more to the absolute differences between arms in events or outcomes of interest rather than to differences expressed with ratio measures like the odds ratio or relative risk. It is the absolute difference between treatments in the number of positive outcomes achieved, or negative outcomes avoided, that will determine the value of the treatment to patients and to society. This remains true regardless if the decision is based on an economic analysis or, for example, on numbers needed to treat.

We therefore distinguish between the model for relative treatment effects, as set out in Chapters 2 and 4, and what we refer to as the baseline model. Technically, this is a model ...