Levels of Evidence within Cardiovascular Medicine Research in Saudi Arabia: A Systematic Review.

International commitments to reduce the prevalence of non-communicable disease have led the Government of Saudi Arabia to invest more in research related to cardiovascular disease. However, the strength of evidence derived from these research activities remains unclear. The aim of our study was to examine the level of evidence within clinical Cardiovascular Medicine research in Saudi Arabia. We conducted a systematic review of published articles that included a population from Saudi Arabia. Electronic databases EMBASE and MEDLINE (Ovid) were searched up to 25^th of April 2021, supplemented by a second search in CENTRAL (Cochrane Central Register of Controlled Trials) and www.clinicaltrials.gov. In addition, the Snowball- and Pearl-growing methods of search were conducted for finding additional eligible articles. Finally, a search was conducted in PubMed database for all eligible articles published by Journal of the Saudi Heart Association from the first indexed issue up to April 2021. Level of evidence of reviewed articles was determined using the Oxford Level of Evidence 2 scale. We calculated the mean level of evidence over 5-year periods, and explored evidence for a time trend for number of published articles and LOE using linear regression. Of the 1113 records identified, 418 met the inclusion criteria for analysis. The articles were published between September 1986 and March 2021. More than half of the included articles were level IV studies (n = 242, 57.8%). Furthermore, we observed no trend over the years for increased mean of level of evidence (β = -0.07, 95% CI [-0.20, -0.06], p = 0.236). Overall, the level of evidence produced by the articles in clinical Cardiovascular Medicine in Saudi Arabia is very low. Prioritizing higher-quality research is critical to produce the clinical practices and policies necessary to reduce the burden of cardiovascular diseases in Saudi Arabia.