The prognosis for asthma is generally good, especially for children with mild disease.[160] Mortality has decreased over the last few decades due to better recognition and improvement in care.[161] Globally it causes moderate or severe disability in 19.4 million people as of 2004 (16 million of which are in low and middle income countries).[162] Of asthma diagnosed during childhood, half of cases will no longer carry the diagnosis after a decade.[56] Airway remodeling is observed, but it is unknown whether these represent harmful or beneficial changes.[163] Early treatment with corticosteroids seems to prevent or ameliorates a decline in lung function.[164]