2. Why Access To Clinical Trial Results Is Important?

The concept of evidence-based medicine (EBM) was created in the early 1980s as clinical practice became more data-driven and literature based. EBM is now an essential part of what is taught at medical school. Information on treatment efficacy and safety is important for making informed treatment decisions by the patients and their physicians.

It is important not to limit the search for evidence about a treatment to a single publication. When comparing results coming from different sources, it is important to keep in mind the different levels of evidence. The hierarchy of evidence relates to the strength of the trial design and statistics deployed and not necessarily to the clinical significance. Randomised, controlled, blinded trials provide the best scientific evidence of benefit and risk but sometimes are not available. Meta-analysis can be flawed because of publication bias.

In general, the hierarchy of trials for obtaining evidence is:

Highest level

Adequately powered, randomised controlled trial, or meta-analysis of randomised trials showing statistically consistent results. 

Randomised trials inadequately powered, possibly biased, or showing statistically inconsistent results. 

Non-randomised trials with concurrent controls. 

Non-randomised trials with historical controls (i.e. typical single arm Phase II trial). 

Bottom level

Expert committee review, case reports, retrospective trials. 

Patients can learn about clinical trial results from their doctor and also by accessing the published information directly. Access to clinical trial results for researchers is paramount for improving the efficiency in research by reducing the duplication or replication of research efforts.