Text and Data Mining valid from 2019-07-02
Received: 28 November 2018
Accepted: 4 June 2019
First Online: 2 July 2019
Ethics approval and consent to participate
: The study protocol was approved by the Johns Hopkins School of Public Health Institutional Review Board, which determined the study to be nonhuman subjects research (IRB No: 00007896) given the use of administrative data.
: Not applicable.
: The authors declare that they have no competing interests.