Introduction Although randomised, controlled trials are important in the development of new pharmacological treatments, they provide limited information on the ‘real life’ management of chronic diseases. Here, we analysed two-year follow-up data from the prospective, non-interventional, observational DACCORD study to evaluate the frequency of exacerbations and the evolution of disease severity using GOLD 2011 categorization.

Methods COPD out-patients were recruited into DACCORD following either a change or initiation of COPD maintenance medication and followed up for 2 years. Data of 3137 patients that completed the 2-year follow-up were analysed; Exacerbation data were collected from the 6 months prior to study entry (baseline), and every 3 months for 2 years after entry; COPD symptoms were evaluated using the COPD Assessment Test (CAT) at baseline as well as the 1 year and 2 year visit.

Results In this cohort the non-exacerbating phenotype was stable with a total of 69.4% of patients without exacerbations in the 6 months prior to baseline not reporting any exacerbation over the full 2 year follow-up period resulting in an annual exacerbation rate of 0.263 in year 1 and 0.251 in year 2. In contrast, patients with at least one exacerbations in the 6 months prior to baseline showed an annual exacerbation rate of 0.770 in year 1 and 0.633 in year 2. At baseline 44.6% of patients were categorised as GOLD D, one third of these due to their exacerbation history alone. In Year 1 there was a general shift to lower risk categories compared to baseline (GOLD D: 44.6% vs. 31.1%) mainly due to a lower number of exacerbations in Year 1. Overall, categorization then remained relatively stable from Year 1 (GOLD D = 31.1%) to Year 2 (GOLD D = 32.1%).

Conclusions Although, COPD is generally considered to be a progressive disease, this analysis of ‘real life’ data over an observational period of 2 years shows that the ‘non-*exacerbating’ phenotype is relatively stable. The data furthermore confirms that exacerbations in the recent history increase the risk of future exacerbations.