title: Control Group and Refusal Rate Critiques about Hepatitis C Virus Infection in HIV Positive Cases.
authors.affiliation: Department of Epidemiology, School of Public Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran ; Center for Educational Research in Medical Sciences, Tehran University of Medical Sciences, Tehran, Iran E-mail: aikabir@yahoo.com.
authors.forename: Ali
authors.initials: A
authors.lastname: Kabir