In our new scoping review, we explored the impact of clinical trial data-sharing initiatives.
We looked at various outcome domains corresponding to the data sharing pipeline: Intention to share data, data sharing, data reuse, research output from shared data and impact of such an output. We searched all studies exploring these outcome domains for various data sharing initiatives. We also looked at online information from the main initiatives/platforms.
We found a bourgeoning literature. 93 studies identified in the literature search (published between 2001 and 2020, median: 2018) and 5 from additional information sources were included in the scoping review.
Most studies were descriptive and focused on early phases of the data-sharing process. Very few were experimental studies and very few explored impact of clinical trial data sharing. We tried to synthesize all outcomes used in all outcome domains. This can be useful for those who would like to design studies about clinical trial data sharing. Could be a starting point for developing a core outcome set.
We provide a description of all the included studies/metrics. While the willingness to share IPD from clinical trials is extremely high, actual data-sharing rates are suboptimal. A survey of journal data suggests poor to moderate enforcement of the policies by publishers. Metrics provided by platforms suggest that a large majority of data remains unrequested. When requested, the purpose of the reuse is more often secondary analyses and meta-analyses, rarely re-analyses.
Main limitations were the following A) retrieval and synthesis of information proved to be difficult because of a very siloed landscape where each initiative/platform operates with its own metrics; B) data sharing is a moving target in a rapidly changing environment.
There is currently a gap in the evidence base evaluating impact of IPD sharing, which causes uncertainties in the implementation and adoption of current data-sharing policies. High level evidence is needed to assess whether the value of medical research increases with data-sharing practices. We need to study more best practices and their impact.