ResApp Health Limited announced that it has enrolled the first patient in its SMARTCOUGH-C-2 study in the United States. The study is a prospective, multi-site, double blind study to evaluate the efficacy of the ResAppDx smartphone application in the diagnosis of childhood respiratory diseases from cough sounds. The SMARTCOUGH-C-2 study plans to enrol up to 1,667 patients aged 29 days to 12 years of age who present to one of the three participating sites in the United States with signs or symptoms of respiratory disease. The study's co-primary endpoints are positive and negative percent agreement with clinical diagnosis for pneumonia, lower respiratory tract disease, viral lower respiratory tract infection, bronchiolitis, asthma/reactive airways disease, upper respiratory tract disease and croup. The clinical diagnosis will be made by an independent, centralised clinical adjudication committee using all available clinical data, including radiology and microbiology.