This article appeared in the Journal of Research in Health Sciences which is published quarterly by the School of Public Health, Hamadan University of Medical Sciences. The attached copy is furnished to the authors for non‐commercial research and educational use. The authors are encouraged to visit currently published articles by JRHS at: http://jrhs.umsha.ac.ir/index.php/JRHS/article/view/1039 Provided for non‐commercial research and education use.