Study finds slight improvement in reporting adverse effects in drug trials over the last 17 years Researchers, including academics from the University of York, analyzed systematic reviews of 1,200 Randomized Controlled Trials (RCTs) to assess whether reporting had improved over time. However, the information the researchers needed to assess what adverse effects were reported (and how they were reported) was only included in less than half of the RCTs they analysed. Drug trials are conducted to give clinicians information on the benefits and adverse effects of treatments. Our study shows that, disappointingly, there's only been a slight improvement in reporting the adverse effects in trials over the last 17 years."