Funding for this research was provided by:
Received: 12 May 2020
Accepted: 17 September 2020
First Online: 28 September 2020
Ethics approval and consent to participate
: The study was approved by the ethics committee of Tehran University of Medical Sciences, and a written informed consent was signed by all participants in the study. Illiterate invitees were asked to visit the study center and to observe the procedures before signing the written informed consent.
: Not Applicable.
: The authors declare no conflict of interest.