Treatment outcome and side effects in patients with acute exacerbation of COPD treated in primary care in the UK before and after the introduction of guidelines endorsing 5 rather than 14 days of oral corticosteroids: a hypothesis-testing study

This study seeks to investigate if the introduction of guidelines introduced in 2015 supporting a shortened OCS course during acute exacerbation of COPD (AECOPD) altered the treatment efficacy and safety. The study population of interest will consist of patients with AECOPD treated with OCS in general practices in the United Kingdom that form part of the CPRD (Clinical Practice Research Datalink). The primary exposure is treatment with OCS before and after the introduction of the guidelines recommending only five days of treatment. The primary outcome is the time to next exacerbation during the 12 months after the index exacerbation. Secondary outcomes will be the number of exacerbations during the 12 months after the index exacerbation; duration of OCS therapy (if available), treatment safety, notably, the number of patients with new onset diabetes during twelve months after AECOPD.