OBJECTIVES:  Daxas (roflumilast) is a new PDE4-inhibitor which targets the underlying inflammation in COPD. It is indicated for treating severe and very severe COPD associated with chronic bronchitis and a history of frequent exacerbations. The objective was to assess the incremental cost-effectiveness of using roflumilast in a Swedish health care setting.The clinical trials for roflumilast have shown that it consistently reduces exacerbations by approx. 20% and that it also provides a lung function benefit of between 46-81 mL in addition to long-acting bronchodilators. METHODS: A Markov model with a life time time horizon, one month cycles and a discount rate of 3%  was constructed using Treeage and an Excel interface. The model uses comparator treatments relevant to Swedish guidelines including long acting β-2 agonist (LABA), inhaled corticosteroids (ICS) and long-acting muscarinic antagonists(LAMA). All input parameters on costs and epidemiology were from Swedish sources.  Clinical effectiveness was based on results from clinical trials along with indirect comparisons to address other comparators relevant to the reimbursement authorities. The analysis had a societal perspective and included lost productivity using a human capital approach. Outcomes were measured in QALYs. Uncertainty was addressed both through probabilistic sensitivity analysis and one-way analyses of central variables.  RESULTS: Treatment with roflumilast (ROFL) as an add-on to LABA resulted in an incremental gain of 0.35 QALY. From a societal perspective the ICER for LABA+ROFLU versus LABA was €18,000 per QALY. The probability that LABA+ROFLU was cost-effective using a €50 000 threshold was 97%. The ICER for LABA+ROFLU vs LABA+ICS was €14,500. ROFLU+LAMA+LABA+ICS vs LAMA+LABA+ICS was €19,000. CONCLUSIONS: The ICERs calculated were all well below commonly accepted willingness to pay for a QALY in Sweden for all different comparator scenarios. The results were stable when central variables were varied. Roflumilast is a cost-effective treatment for severe and very severe COPD.