Funding for this research was provided by:
Public Health England
Received: 17 December 2021
Accepted: 7 July 2022
First Online: 17 July 2022
: Ethical approval was granted on 4 May 2021 by the London School of Hygiene and Tropical Medicine Observational Research Ethics Committee (Ethics Ref: 22987). Informed consent was obtained verbally, prior to the cognitive interviews and informed consent from survey respondents was obtained online, prior to questionnaire completion. Both procedures for obtaining informed consent were approved by the above ethics committee. All methods were performed in accordance with the Declaration of Helsinki.
: Not applicable.
: The authors declare that they have no competing interests.