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. 2016 Dec 21;12:59–71. doi: 10.2147/COPD.S117196

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© 2017 Bosnic-Anticevich et al. This work is published and licensed by Dove Medical Press Limited

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Flow diagram showing study cohorts derived from Optimum Patient Care Research Database.

Notes: ^aMatching variables included are as follows: age, sex, body mass index, smoking status, forced expiratory volume in 1 second % predicted, number of moderate/severe exacerbations during baseline year, number of types of COPD treatment, active asthma and index year. Matching variables were derived from exploratory analysis of 1 year of baseline data.