Just 1 out of 10 treatments backed by high-quality evidence
Quality of studies behind most healthcare interventions 'remains low' and needs to lift: authors
Only one in 10 medical treatments are backed by high-quality evidence, according to a review of Cochrane findings. 
International researchers looked at the primary outcome of 151 Cochrane systematic reviews published between 2015 and 2019 that were updates of earlier (2013-14) reviews to see whether the quality of evidence had improved over time. 
They assessed them against the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system to document the evidence quality.
In the reviews analysed, 10% had high-quality evidence supporting the first-listed primary outcome, 37% had moderate, 31% had low, and 22% had very low-quality evidence,” they wrote in the Journal of Clinical Epidemiology. 
