Status, use and impact of sharing individual participant data from clinical trials: a scoping review

Abstract

Objectives: To explore the impact of data-sharing initiatives on the intent to share data, on actual data sharing, on the use of shared data and on research output and impact of shared data.

Eligibility criteria: All studies investigating data-sharing practices for individual participant data (IPD) from clinical trials.

Sources of evidence: We searched the Medline database, the Cochrane Library, the Science Citation Index Expanded and the Social Sciences Citation Index via Web of Science, and preprints and proceedings of the International Congress on Peer Review and Scientific Publication. In addition, we inspected major clinical trial data-sharing platforms, contacted major journals/publishers, editorial groups and some funders.

Charting methods: Two reviewers independently extracted information on methods and results from resources identified using a standardised questionnaire. A map of the extracted data was constructed and accompanied by a narrative summary for each outcome domain.

Results: 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. 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. Finally, studies focused on the real impact of data-sharing were rare and used surrogates such as citation metrics.

Conclusions: There is currently a gap in the evidence base for the impact of IPD sharing, which entails uncertainties in the implementation of current data-sharing policies. High level evidence is needed to assess whether the value of medical research increases with data-sharing practices.

Keywords: health informatics; information management; information technology.

Figure 1

PRISMA flow diagram. *For National Institute of Health USA, the answer we received was not informative. IPD, individual participant data; PRISMA, Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

Figure 2

Proportion of the 93 references exploring each outcome domain. Study designs considered. Experimental: prospective research that implies testing the impact a strategy (eg, randomised controlled trial). Survey: a general overview, exploration or description of individuals and/or research objects. Metrics: descriptive metrics from each initiative provided by the initiative. Qualitative: research that relies on non-numerical data to understand concepts, opinions or experiences. Other: any other research not covered above (eg, case studies, environmental scans).

Figure 3

Outcomes used to assess current data-sharing practices for individual patient data for clinical trials organised per outcome domain and number of studies exploring these outcomes. Study designs considered. Experimental: prospective research that implies testing the impact a strategy (eg, randomised controlled trial). Survey: a general view, exploration or description of individuals and/or research objects. Metrics: descriptive metrics from each initiative provided by the initiative. Qualitative: research that relies on non-numerical data to understand concepts, opinions or experiences. Other: any other research not covered above (eg, case studies, environmental scans). IPD, individual participant data.

Figure 4

Intent to share. Numbers correspond to the numbers of cases with the outcome/number of cases reported in each reference. ^aThe proportion is 73% if the purpose is a reanalysis. ^bFifty-four participants out of 60 had an opinion about data-sharing (the others had no knowledge or no opinion). ^cAn additional 25% were undecided. ^dThe proportion is 19% for requiring a data-sharing plan. ^eThirty-five per cent have a data-sharing policy (encouraging data-sharing). ^fOnly two with a mandatory policy. ^gThe proportion is 71% for a sample of all companies (not only the top 25). In DeVito et al, we extracted the information on policies that made data-sharing mandatory (ie, a requirement to share the data). CTUs, Clinical Trial Units; ICMJE, International Committee of Medical Journal Editors; IPD, individual participant data; RCT, randomised controlled trial.

Figure 5

Actual data sharing. Numbers correspond to the numbers of cases with the outcome/number of cases reported in each reference. CSDR, Clinical StudyDataRequest.com; CTU, Clinical Trial Unit; IPD, individual participant data; PLOS, Public Library of Science; SOAR, Supporting Open Access for Research Initiative; RCT, randomised controlled trial; YODA, Yale University Open Data Access.

Figure 6

Temporal trends, number and type of published output from CSDR and YODA. Blue: YODA. Red: CSDR. CSDR, ClinicalStudyDataRequest.com; YODA, Yale University Open Data Access.