Funding for this research was provided by:
Student Research Committee of Ilam University of Medical Science (22/52/2888)
Text and Data Mining valid from 2018-04-26
Received: 26 June 2017
Accepted: 15 March 2018
First Online: 26 April 2018
Ethics approval and consent to participate
: Consent to participate is not applicable in this study, because it is a systematic review and meta-analysis study.
: Not applicable.
: The authors declare that they have no competing interests.
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