Background: Individual participant data (IPD) meta-analyses rely on the availability of raw IPD. Yet, calls for open data and data sharing seem to often go unheard and many IPD meta-analyses struggle to attain sufficient IPD. The practice and culture of data sharing might be improved if data sharing policies were prominent and actionable at all stages of the research process.
Objectives: To describe the epidemiology of data sharing policies across the health research lifecycle and identify pathways to improve rates of data sharing.
Methods: This was a cross-sectional study, describing the epidemiology of data sharing policies of major stakeholders across the health research lifecycle. We included the following major stakeholders in medical research: the largest public, philanthropic, and private funders, all national ethics committees, all primary clinical trial registries, the 5 highest-impact journals for each of the 59 fields of medicine, and all research data repositories. We assessed each stakeholder for the presence of a data sharing policy, magnitude of support for data sharing (data sharing mentioned, recommended, or required), policy characteristics, and COVID-19 specific policies.
Results: We included 935 stakeholders: 110 funders (55 public or philanthropic, and 55 private), 124 ethics committees, 18 trial registries, 273 journals, and 410 data repositories. Data sharing was required by 41% (45/110) of funders, no ethics committees or trial registries, 19% (52/273) of journals, and 6% (24/410) of data repositories (Figure 1). Private pharmaceutical and biotechnology funders were 6.3 times more likely than public funders to require data sharing. Among those requiring data sharing, limited guidance was provided on what, when, who with, how, and why to share data. No stakeholders required data sharing specifically for COVID-19 studies.
Conclusions: Increased data sharing rates are crucial to enable IPD meta-analysis. Calls for data sharing have accelerated, but major stakeholders across the health research lifecycle provided limited requirements or guidance to ensure the scientific and ethical imperatives for data sharing are met. We see particular opportunities to increase data sharing rates for public funders and ethics committees. Patient, public, and/or healthcare consumer involvement: IPD meta-analyses frequently inform guidelines that directly inform how patients are treated.

Figure 1. Data sharing policies by stakeholders.png