Authors: Raghu G, Amatto VC, Behr J, Stowasser S Abstract Idiopathic pulmonary fibrosis (IPF) is associated with a fatal prognosis and manifests in patients over 60 years old who may have comorbidities. The prevalence and impact of comorbidities on the clinical course of IPF is unclear.This systematic literature review examined the prevalence of comorbidities and mortality associated with comorbidities in IPF patients. Relevant observational studies published in English from January 1990 to January 2015 identified via MEDLINE and EMBASE were included; bibliographies of articles were also searched.Among the 126 studies included, prevalence of pulmonary hypertension (PH) was 3-86%, 6-91% for obstructive sleep apnoea, 3-48% for lung cancer and 6-67% for chronic obstructive pulmonary...