Received: 25 July 2018
Accepted: 4 February 2019
First Online: 15 February 2019
Ethics approval and consent to participate
: This study was approved by the Hacettepe University Ethical Committee (# GO 14/ 04–06). Participation in this study was voluntary. Before replying to the questions an informed consent form was signed by the participants. Anonymity and confidentiality were considered in all stages of the study.
: Not applicable.
: The authors declare that they have no competing interests.
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