13.1  Introduction

13.1.1 What this chapter is about

Box 13.1.a: Some types of NRS design used for evaluating the effects of interventions

13.1.2 Why consider non-randomized studies?

13.1.3 Key issues about the inclusion of non-randomized studies in a Cochrane review

13.1.4 The importance of a protocol for a Cochrane review that includes non-randomized studies

13.1.5 Structure of subsequent sections in the chapter