OBJECTIVES: Roflumilast is an oral, once-daily PDE 4 inhibitor under investigation for COPD and asthma therapy. This study investigated the cost-effectiveness of Roflumilast in patients with severe to very severe COPD, including the financial impact on the UK healthcare system. METHODS: The analysis was conducted alongside a randomised, placebo-controlled, multinational trial (M2-112) evaluating the efficacy of roflumilast in terms of lung function and the frequency of moderate and severe (mod/sev) exacerbations in severe and very severe COPD patients. COPD-related healthcare use and absence from work were recorded. Differences in costs were related to differences in number of mod/sev exacerbations. Trial wide resource use was multiplied with 2004 UK unit cost. A total of 1505 COPD patients with post FEV1% pred