Ban WH, et al. - In this cross-sectional study, researchers used COPD assessment test (CAT) and insomnia severity index (ISI) data from patients undergoing treatment for COPD at St Paul’s Hospital, The Catholic University of Korea, between December 2015 and August 2016 to determine the prevalence of insomnia and the association between insomnia and health status in patients with COPD. They studied clinical parameters, including past medical history, pulmonary function tests, along with questionnaire data for all patients grouped as a “clinical insomnia” group (ISI ≥ 15), a “subthreshold insomnia” group (ISI 8–15), and a “non-insomnia” group (ISI < 8). They found a close association between CAT score and insomnia severity in patients with COPD. Use of CAT scores may allow for better detection and management and improve clinical practice.