First Online: 12 November 2019
Ethics approval and consent to participate
: The CALIBER programme has been approved by a NHS Research Ethics Committee (09/H0810/16). This study was approved by the CPRD Independent Scientific Advisory Committee (protocol 12_117). Individual patient consent is not required for observational CPRD studies, but patients have the opportunity to opt out of contributing to the database.
: Not applicable.
: The authors declare that they have no competing interests.