Health literacy among Iranian adults: findings from a nationwide population-based survey in 2015Ali Akbar Haghdoost, Mohammad Karamouzian, Ensiyeh Jamshidi, Hamid Sharifi, Fatemeh Rakhshani, Nadia Mashayekhi, Hamid Rassafiani,Fatemeh Harofteh, Mansoor Shiri, Mohammad Aligol, Hossein Sotudeh, Atoosa Solimanian, Fatemeh Tavakoli and Abedin Iranpour