sima rafiei department of health management, school of health, qazvin university of medical sciences, qazvin, iran mohammad arab department of management and health economics, school of public health, tehran university of medical sciences, tehran, iran arash rashidian department of management and health economics, school of public health, tehran university of medical sciences, tehran, iran mahmood mahmoudi department of epidemiology and biostatistics, school of public health, tehran university of medical sciences, tehran, iran vafa rahimi-movaghar sina trauma and surgery research center, sina hospital, tehran university of medical sciences, tehran, iran