We identified six full economic evaluations assessing the cost and cost-effectiveness of tiotropium and salmeterol. The studies were based on an economic model or empirical analysis of clinical data from RCTs . They all looked at maintenance costs and the costs for COPD exacerbations, including respiratory medications and hospitalisations. The setting for the evaluations was primary and secondary care in the UK, Greece, Netherlands, Spain and USA. All the studies estimated tiotropium to be superior to salmeterol based on better clinical outcomes (exacerbations or quality of life) and/or lower total costs. However, the authors of all evaluations reported there was substantial uncertainty around the results.