Efficacy and Safety of Indacaterol vs Tiotropium in Women With COPD Secondary to Biomass Exposure

Chronic Obstructive Pulmonary Disease (COPD) is a disease that produces a high rate of social and economic health mortality and morbidity not only in our country but in the international field. The causes of this disease are well-known, being smoking what produces the major portion and the less (but no less important) frequently, biomass exposure (when people cook or warm the house). It is described that the COPD secondary to biomass exposure it is approximately a third half of all the cases in cohorts in patients with this disease. Patients clinical affection with COPD by biomass is different from the one described in patients by smoking, being the most frequent the affection peripheral airway, with major proportion of symptoms such as dyspnoea, cough and expectoration (Phenotype "chronic bronchitis"), major frequency of exacerbations, as well as, major affection in the quality of life related to health and a minimum emphysema proportion. Currently, there is a trend of paying attention on the outcomes based on patients, such as symptoms, quality of life and the risk prevention (exacerbations) as it is exposed in the strategy GOLD 2011. In that way, the bronchodilators use as a pillar in the COPD due to the utility for the exacerbation prevention, symptomatic improvement and in quality of life, predominating the utility of ultra long-acting bronchodilators, such as tiotropium. Recently, it is available more information on new bronchodilators as indacaterol, demonstrating at least no inferiority effect on FEV1, inspiring capacity (in fact, discreet superiority on the last one) and symptoms. A functional outcome clinically important is the capacity of exercising; Six-Minute Walk Test (6MWT) has been widely used to predict prognosis of COPD secondary to smoking. This test has not been evaluated in predicting the response to the specific treatment in patients with COPD secondary to biomass exposure. Long-acting bronchodilators have been demonstrated a benefit to the patients with COPD by smoking, in the exercising capacity measured by 6MWT. There are several reasons why this outcome could be more relevant especially in this population: inhabit in rural areas where people walk long distances, most of them are women and they are usually in charge of all the housework. Almost all the studies reported until now exclude patients with COPD due to some cause other than smoking. Due to the lack of information on this item and the particularities in this clinical and functional characteristics observed in this kind of patients, it is considered that these patients will be benefit with the use of ultra long-acting bronchodilators, to long period and, potentially can be observed additional benefits in the decrease of the frequency of the exacerbations and symptomatology as well as other important outcomes such as the functional, respiratory capacity among others.

The use of bronchodilators is an invaluable tool in COPD, in outcomes such as the exacerbation preventions, improvement of symptoms and exercise capacity and therefore in quality of life. However, as the efficacy as the security such as bronchodilators benefits that have only been characterized in patients with COPD secondary to smoking and it is only assumed benefits in COPD by other causes but without confirmation. There are no national or international studies that describe the ultra long-acting bronchodilator's efficacy and security in COPD secondary to biomass exposure (BE). The proportion of patients with COPD secondary by biomass exposure vary between 20-30%, depending on what kind of study and population, which is an important number leading to a great mortality, morbidity, social and economic, being important to characterize in a better way several relevant aspects such as the long period treatment response. The proportion of patients with COPD by BE presents major proportion of phenotype "bronchitis" with major condition of peripheral airways level, with major proportion of dyspnoea and a decrease in the quality of life. It is precisely in these aspects where have been demonstrated benefits with ultra long-acting bronchodilators, as consequence, it is expected that this group of patients will be benefitted equal and perhaps in greater magnitude that those that are encompassed in the "emphysematous" phenotype. Additionally, it is well described that the sub-diagnostic and sub-optimum treatment in patients with COPD in first level; because this kind of patients generally have low social-economic status and assuming that in the first level they will find the principal attention, it would be important to define major therapeutic alternatives in them. As it was mentioned before, the exercising capacity is a functional outcome deeply studied with prognostic capacity in patients with COPD secondary to smoking; it is probably that it could be an outcome with major impact in this special group of patients (COPD secondary to biomass exposure), because they live, in general, in rural areas, heads of household and therefore, in terms of social rolls their functionality requirement is higher. Finally, there is a finding well described the low adherence to patient's treatment with COPD, with various reasons including low economic resources and others such as devices of complicated application, multiple dosage, etc. Due to the fact that most of the people who suffer COPD by biomass exposure are women dedicated to housework all the day, it is probable that this kind of medicines (dosage once a day) as well as free treatment, is a strategy that improves the treatment adherence and could represent an improvement in the important outcomes in this devastating disease (functional capacity, quality of life, frequency of exacerbations, mortality).