Level of evidence in interventional studies presented at a Brazilian congress of vascular surgery


Oral session: Global health and equity (2)


Wednesday 23 October 2019 - 11:00 to 12:30


All authors in correct order:

Périco Silveira B1, Estrutti C1, Medina M1, Amaral F1, Piber L1, Cassola N1, Prestes O1, Guedes LG1, Flumignan C1, Vasconcelos V1, Nakano L1, Amorim J1, Baptista-Silva J1, Flumignan R1, Guedes H1
1 Division of Vascular and Endovascular Surgery, Universidade Federal de São Paulo, Brazil, Brazil
Presenting author and contact person

Presenting author:

Beatriz Périco Silveira

Contact person:

Abstract text
Background: the level of evidence (LOE) presented and discussed in a scientific meeting is a growing concern in academia, with evidence-based medicine gaining more space and guiding clinical decisions regarding diagnoses and behaviours in various areas. Thus, it is expected that scientific works presented at medical congresses have improved their LOE, seeking to progress more and more with the discussions and the emergence of new techniques and guidelines that improve patient care. Since medicine is now evidence-based, it is expected that the high level of evidence has gained in importance and has been discussed more over the last few years.

Objectives: to evaluate the LOE presented in the Brazilian congresses of vascular surgery between 2014 and 2018.

Methods: we searched all Brazilian congresses of vascular surgery of 2014 and 2018 but only one congress had its abstracts retrieved because only the Congresso Internacional de Cirurgia Endovascular (CICE) published their results. We contacted the other two great national congresses of vascular surgery, but unfortunately their abstracts were not available.

We conducted a search in the annals of the CICE congress, screening all the abstracts presented in the years 2014 and 2018. We classified all the papers according to the information contained in the published abstracts and according to the scale of level of scientific evidence by type of study from the Oxford Centre for Evidence-Based Medicine. Subsequently, we calculated the average level of scientific evidence of the two years and considered studies that dealt with experimental studies or with non-human models not to be relevant to the analysis.

Results: for the year 2014, we included 110 studies and most were of very low LOE (52% case reports). For the year 2018, we included 126 articles, and most were of very low LOE (61% case reports). The highest level of evidence, systematic reviews of randomized controlled trials, did not figure in the setting of this congress, either in 2014 or in 2018. We did not identify any relevant difference in LOE between the abstracts of 2014 and 2018. See figure.

Conclusions: we concluded that the studies presented in the only available Brazilian congress of vascular surgery were of very low LOE, in most of the case reports. Although there are a number of high-quality studies, including Cochrane systematic reviews related to vascular surgery and produced in Brazil, these works are not presented in the Brazilian congress that provides their abstracts for readers. It is mandatory to disseminate the best available evidence in vascular surgery at Brazilian scientific events, to improve confidence in the presented data.

Patient involvement: patient-centred outcomes and questions relevant to patients should be the focus of all scientific meetings, but the Brazilian congresses of vascular surgery have capacity to improve discussion about the best available evidence.