Ethics approval and consent to participate
The study protocol was subject to favourable opinion by the South Birmingham Research Ethics Committee (Ref: 17/WM/0381) and institutional review board of University Hospitals Birmingham (Ref: RRK6082). Eligible patients were approached, given written and verbal information about the study, and given sufficient opportunity to consider the information before giving their consent to join the cohort study. The study was conducted in accordance with the Declaration of Helsinki.