Real-world data: A relevant component in the framework of scientific evidence.

Explanatory randomized controlled clinical trials test hypotheses to see if the intervention causes an outcome of interest in optimal circumstances, that is, established by selecting patients based on inclusion and exclusion criteria and controlled environments. They assess the "efficacy" of an intervention. On the contrary, it is crucial for society to address issues related to real-world clinical practices. This need can be fulfilled by real-world studies. We discuss the challenges in obtaining real-world evidence in asthma, debating the importance of including patients who are typically excluded from randomized controlled clinical trials to ensure the generalizability of the results. We conclude by discussing the integration of real-world evidence in guidelines and the need for standard rules to use real-world evidence in guidelines.