OBJECTIVES:  Coexistence of Asthma and Chronic Obstructive Pulmonary Disease is defined as overlap syndrome. Large variations have been observed in the published p­­revalence estimates of ACOS due to ambiguity in the disease definitions. The aim of this systematic review and meta-analysis was to update the prevalence estimate of ACOS and analyze trends in epidemiology, and the associated economic and humanistic burden (Alshabanat et al., 2015). METHODS: