Funding for this research was provided by:
Economic and Social Research Council (ES/P000177/1)
Received: 27 March 2019
Accepted: 30 October 2019
First Online: 12 November 2019
Ethics approval and consent to participate
: EXTEND conducts secondary analyses on the data collected within the participating cohort studies. All participating cohort studies have originally received consent of the participants and ethical approval from their respected institutions.
: Not applicable.
: The authors declare that they have no competing interests.