Funding for this research was provided by:
Medical Research Council (Doctoral Training Partnership)
Received: 15 January 2020
Accepted: 14 July 2020
First Online: 10 September 2020
Ethics approval and consent to participate
: This study used publically available country-level routine data sources and as such was exempt from ethical review.
: Not applicable.
: The authors declare that they have no competing interests.