Four Decades of Randomized Clinical Trials Influencing Mortality in Critically Ill and Perioperative Patients

Randomized clinical trials (RCTs) represent the highest level of scientific evidence. The aim of this review was to map and summarize the main characteristics and publication trends of RCTs with a statistically significant effect on mortality in critically ill and perioperative patients.

A mapping review of RCTs published between January 1982 and January 2021. The authors searched PubMed/MEDLINE and EMBASE for RCTs reporting mortality data. A descriptive analysis was conducted, including general and methodologic information of all these RCTs with a statistically significant difference (p < 0.05) in mortality.

The authors identified 340 studies published in 115 journals from 42 countries. The most represented clinical areas were ventilatory support (n = 58, 17%) and hemodynamics (n = 56, 16%). A detrimental effect on survival was described in 47 (14%) RCTs. Denmark had the highest number of published trials per million inhabitants. A total of 40 (12%) RCTs were led by a female author. The intention-to-treat principle was applied overall in 60% of RCTs, though this percentage increased up to 75% when the study was published in journals with high impact factor.

In the largest contemporary RCTs database of interventions significantly influencing mortality, the authors found an increase in scientific production. United States, China, France, Italy, and the United Kingdom contributed with 172 (51%) RCTs over 40 years. Only 20% of the studies were multinational collaborations, though this percentage increased over time. The presence of women as first authors was 1 out of 8 RCTs.