Randomized Controlled Trials and real life studies. Approaches and methodologies: a clinical point of view.

Randomized Controlled Trials (RCTs) are the "gold standard" for evaluating treatment outcomes providing information on treatments "efficacy". They are designed to test a therapeutic hypothesis under optimal setting in the absence of confounding factors. For this reason they have high internal validity. The strict and controlled conditions in which they are conducted, leads to low generalizability because they are performed in conditions very different from real life usual care. Conversely, real life studies inform on the "effectiveness" of a treatment, that is, the measure of the extent to which an intervention does what is intended to do in routine circumstances. At variance to RCTs, real life trials have high generalizability, but low internal validity. Recently the number of real life studies has been rapidly growing in different areas of respiratory medicine, particularly in asthma and COPD. The role of such studies is becoming a hot topic in respiratory medicine, attracting research interest and debate. In the first part of this review we discuss some of the advantages and disadvantages of different types of RCTs and analyze the strengths and weaknesses of real life trials, considering the recent examples of some studies conducted in COPD. We then discuss methodological approaches and options to overcome some of the limitations of real life studies. Comparing the conclusions of effectiveness and efficacy trials can provide important pieces of information. Indeed, these approaches can result complementary, and they can guide the interpretation of each other results.

Bronchial glomus tumor mimicking a COPD exacerbation.

We report the case of a glomus tumor originating in the left main bronchus diagnosed in a 79 year old Caucasian man. A glomus tumor is an extremely rare neoplasm in the bronchi with nonspecific clinical features. Bronchoscopy allows the diagnosis through biopsy and subsequent histopathological examination of the tissue and in selected cases may represent a valid alternative to surgery permitting a radical tumor excision.

Viral infections in exacerbations of asthma and chronic obstructive pulmonary disease.

Respiratory viral infections are recognized as the most frequent cause of asthma and chronic obstructive pulmonary disease (COPD) exacerbations with rhinovirus (i.e. the virus of the common cold) being the most frequent identified virus. The recent development of human experimental models of rhinovirus-induced asthma and COPD exacerbations represent innovative tools with the potential to increase our understanding in this field. Moreover this models will provide the opportunity to test, in a carefully controlled setting, novel pharmacological compounds. In this review we will provide an overview of the role of viral infections in asthma and COPD exacerbations and in particular we will summarize the inflammatory and immunological mechanisms that can pave the way to exacerbation following respiratory viral infection in these patients.