“…Most studies are hospital-based (71%), and one is a multicentre study conducted in 6 counties (13). Only 6 studies are population-based (18,23,27,34,35,39), 3 are multicultural (27,34,35), and only 1 study reports national data (18). The study population is urban in 1 study (13), mixed in 4 studies (18,27,35,39), and unknown in 16 studies (76%).…”