Introduction and rationale: Pulmonary function tests can contribute to a proper diagnosis of asthma in children. This study was aimed to estimate the diagnostic accuracy of impulse oscillometry (IOS) for asthma using the GINA (Global Strategy for Asthma Management and Prevention) criteria and the asthma predictive index (API) as the reference (gold standard). Methods: a cross-sectional study for diagnostic test was designed. Preschool children aged 3 to 6 years old from the Pediatric Pulmonary Section of the Fundación Neumológica
