## 1 Introduction  
Chronic obstructive pulmonary disease (COPD) is a lung inflammatory disease characterized by unreversible restriction in the airflow. Inflammatory mechanisms are considered as partially preventable causes of accelerated lung aging in patients with COPD [1]. Inhaled bronchodilators (both \(\beta\)2-adrenergic agonists and anticholinergics) are the cornerstone of COPD therapy decreasing the frequency of exacerbations, and improving exercise capacity and health-related quality of life (HR-QoL) [2]. Inhaled corticosteroids (ICS) as anti-inflammatory drugs are recommended by GOLD guidelines in combination with a long-acting \(\beta\)2-adrenoceptor agonist (LABA) in moderate-to-very-severe COPD with repeated exacerbations [2].  
A new generic salmeterol and fluticasone propionate fix-combination multidose predisensed dry powder inhaler (DPI), Salflumix Easylaher(r) (Orion Pharma, Espoo, Finland),was approved in 2018 in the European Union (EU) for the therapy of patients suffering from asthma or COPD. It was registered based on an open, single-center, randomized study confirming bioequivalence with the original product developed by GlaxoSmithKline, marketed in the EU as Seretide Diskus(r) and in the US as Advair Diskus(r) (patent expired in 2016). This was a pharmacokinetic four-period crossover study that compared the lung deposition and total systemic exposure of the originator and second-entry product after single-dose administration (two inhalations of 50/500 \(\upmu\)g/inhalation strength) in 65 fasting healthy volunteers ([PERSON], 2018).  
The efficacy of salmeterol and fluticasone propionate combined therapy was shown in a randomized, double-blind TORCH (towards a revolution in COPD health) trial ([PERSON], 2018). This study showed a trend towards improved survival in patients receiving fix-dose combination therapy compared to non-users of ICS and LABA. In addition, there was a significant reduction in rates of exacerbation and forced expiratory volume in one second (FEV1) decline among those treated with the fix-dose combination therapy with moderate-to-severe COPD ([PERSON], 2018). The combined therapy was associated with an increased risk of non-fatal pneumonia ([PERSON], 2018), not overweighting the clear clinical benefits.  
Salflumix Easyhaler(r) differs from the original product and other salmeterol and fluticasone propionate generics by the drug delivery system of Easyhaler(r), developed by Orion Pharma (Espoo, Finland). This high resistance DPI system offers greater consistency of drug delivery during inhalation sufficiently forceful to de-aggregate the drug powdered into breathable-sized particles ([PERSON], 2018). Contrary metered dose inhalers (MDIs) are considered less dependent on a patient's ability to produce airflow than DPIs are; however, patients may have difficulties in coordinating device activation and inhalation, which can be overcome with the use of a spacer (a valved holding chamber) ([PERSON], 2018). Of note, hydrofluorocarbons (HFCs) as MDIs propellants are greenhouse gases with a high global warming potential ([PERSON], 2018). Therefore, the use of MDIs has environmental consequences.  
Since Salflumix Easyhaler(r) launching in Poland in 2018, it was the first study assessing the efficacy and safety of this medical product. This study aimed to assess firstly, effectiveness and secondly, tolerance of Salflumix Easyhaler(r) when given as a first ICS/LABA combination in already treated and newly diagnosed patients with COPD in real-life settings. In addition, this study assessed patients' satisfaction, errors, and burden related to its use, adherence, as well as physicians' perception of this product's overall use.