Prevalence and associated factors of true hypertension among primary school children in the Klang Valley: A cross - sectional study by Devaraj, Navin Kumar, Saeed Ghaloo, Sobia, Ponnudurai, Regan Fu, Kamalan, Vanessa Rohini, Ling, Ying Wong, Kaneson, Vishalini, Abdul Halim, Suriani Akbar