Considerações sobre o uso de evidências científicas em tempos de pandemia: o caso da COVID-19

Abstract

Making better use of available evidence on drugs and non-pharmacological therapies in the context of the Covid-19 pandemic is critical to minimizing suffering and saving lives. This debate aimed to present considerations about the concept of evidence, the hierarchy of evidence and the types of scientific evidence, seeking application in the context of the Covid-19 pandemic, with regard to the use of therapies for prevention and treatment of the disease. Initially, we made a brief introduction on the topic, highlighting the existence of doubts regarding the use of various drugs, as well as whether those available to combat other diseases can be safe and effective in the treatment of Covid-19. Then, we present some definitions about evidence, reinforcing that an exact definition depends on the context in which it will be used, and may even have a broad or restrictive connotation. Next, we mention that the evidence is classified in a hierarchical order, illustrated by means of a pyramid, according to the design of the study employed, one of the important markers to define the quality of the evidence. Emphasis is given to the evidence from the expert opinion, which is based on beliefs built on the basis of theory and non-systematic learning. Soon after, we resorted to basic concepts about three types of scientific evidence (direct, indirect and preliminary evidence) to explain the divergences between expert opinions. We conclude with comments and reflections on the need to define reasonably acceptable criteria for the use of evidence, for now available, in times of a pandemic, such as Covid-19.