Article History
Received: 8 January 2020
Accepted: 2 June 2020
First Online: 10 June 2020
Ethics approval and consent to participate
: The Tolerability and Ethics Committee at the School of Pharmaceutical Science and Technology in Tianjin University waived the requirement of ethics approval for the current study as this was a retrospectively observational study using the de-identified medical claims data. The raw data for this study were obtained from the UEBMI claims of the city of Tianjin, through a formal request to Tianjin Municipal Human Resources and Social Security Bureau for research purposes.
: Not applicable.
: The authors declare that they have no competing interests.