Exploring broad consent in the context of the 100,000 Genomes Project: a mixed methods study.

The 100,000 Genomes Project (100kGP)-a hybrid clinical-research initiative-was set up to analyse whole-genome sequences (WGS) from patients living with a rare disease or cancer. The project positioned participant consent as being of central importance, but consent in the context of genomic testing raises challenging issues. In this mixed method study, we surveyed 1337 100kGP participants regarding their experiences of taking part in the project and conducted in-depth interviews with 24 survey respondents to explore these findings further. Survey responses were analysed using descriptive statistics and interview data were analysed thematically. The consent approach of the 100kGP resulted in a proportion of our study's participants not understanding the complexities of the project and what types of results they might receive; for example, 20% of participants who we surveyed from the cancer arm did not recall what decisions they had made regarding additional findings. It is not surprising that a project such as this, with such diverse aims and participant groups, would throw up at least some challenges. However, participants reported being satisfied with their experience of the project to date. Our study highlights that in the context of consent for more complex endeavours, such as the 100kGP, it is important to assess (and document) an agreement to take part, but complicated decisions about what and when to communicate may need revisiting over time in response to changing contexts. We discuss the implications of our findings with reference to participants of the 100kGP and the newly formed NHS Genomic Medicine Service.