REVIEW   

Minerva Respiratory Medicine 2021 March;60(1):10-5

DOI: 10.23736/S2784-8477.20.01868-4

Copyright © 2020 EDIZIONI MINERVA MEDICA

lingua: Inglese

Randomized controlled trials versus real-life studies: bridging the gap

Gioacchino RICCARDO ¹, Renato FALZARANO ¹, Maria S. MAGNONI ¹ ✉, Gianmarco BENSO ¹, Vincenzo BOCCHINO ², Francesco SQUILLANTE ²

¹ GSK Medical and Scientific Department, GlaxoSmithKline, Verona, Italy; ² Unit of Respiratory Subintensive Care (UTSIR), Monaldi Hospital, Naples, Italy

The role of randomized controlled trials (RCTs) and real-life studies is a hot topic in respiratory medicine, raising a debate on study designs required to answer different questions about optimum use of available strategies. The aim of this review is to discuss some of the advantages and disadvantages of both types of studies. RCTs are designed to minimize extraneous variables so that a direct cause-and-effect relationship can be discerned between an intervention and an observed outcome. For these reasons they are considered the gold standard for evaluating treatment efficacy according to registration requirements. However, due to their strict inclusion criteria, RCTs exclude a high percentage of routine care populations. Thus, RCT have high internal validity but low generalizability. Conversely, real life studies explore the “effectiveness” of a treatment in routine circumstances, i.e. in a large unselected patient population that is representative of the general population, with outcomes that are often excluded from RCTs. The main limitation of real-life studies is the lack of randomization, so that factors potentially influencing the outcomes might be not equally distributed among the different arms. The Salford Lung Study (SLS) on chronic obstructive pulmonary disease (COPD) may represent a bridge between these two types of studies, being the first randomized controlled trial that compared the real-world effectiveness of a novel once-daily investigational medicine (fluticasone furoate/vilanterol) with existing therapy for COPD in routine primary care. Results from RCTs and real-life studies can provide complementary information on efficacy and effectiveness of therapies that can guide clinical practice and should be viewed as complementary approaches to clinical research. The gap between these two types of studies can be bridged by pragmatic randomized studies like SLS, which combines the scientific rigor of a randomized controlled trial with a good approximation of real-world practice.

KEY WORDS: Randomized controlled trials as topic; Pragmatic clinical trials as topic; Asthma; Chronic obstructive pulmonary disease; Evaluation studies as topic; Fluticasone furoate-vilanterol trifenatate