ʻO nā huahana e lawelawe ana i nā pono olakino o ka lehulehu. Wahi a WHO, pono e loaʻa kēia mau huahana "i nā manawa a pau, i ka nui kūpono, i nā ʻano dosage kūpono, me ka ʻike kūpono a me ka ʻike kūpono, a ma ke kumukūʻai hiki i ke kanaka a me ke kaiāulu ke loaʻa".