Communicating information about overdetection: How it affects women's views and decisions about breast cancer screening

Abstract

This thesis investigates how information about overdetection of breast cancer in mammography screening could be communicated to women, and how such information may affect women’s decisions about whether to undergo breast screening. After an introductory chapter, the thesis presents five published papers. Chapter 2 provides an overview of the issues around informed choice in breast screening, highlights previous studies illuminating women’s perspectives on screening, and discusses potential challenges for efforts to achieve better informed decision making in women. Chapter 3 presents a qualitative focus group study which explored women’s responses to the concept of overdetection and different estimates of its rate. The remaining papers relate to a randomised controlled trial designed to investigate the consequences of informing women about overdetection using a written resource. Chapter 4 details the trial protocol. Chapter 5 describes the multi-stage process through which the content of the focus group presentation was adapted into a decision aid, extensively pilot tested using qualitative and quantitative methods, and iteratively revised before starting the trial. Chapter 6 presents findings from the trial, addressing the question of whether including overdetection information in a decision aid improved the rate of informed choice. The thesis ends with a discussion and conclusions chapter.