Data-sharing policies in randomized clinical trials (RCTs) should have an evaluation component. The main objective of this case–control study was to assess the impact of published re-uses of RCT data in terms of media attention (Altmetric) and citation rates.
Re-uses of RCT data published up to December 2019 (cases) were searched for by two reviewers on 3 repositories (CSDR, YODA project, and Vivli) and matched to control papers published in the same journal. The Altmetric Attention Score (primary outcome), components of this score (e.g. mention of policy sources, media attention) and the total number of citations were compared between these two groups.
89 re-uses were identified: 48 (53.9%) secondary analyses, 34 (38.2%) meta-analyses, 4 (4.5%) methodological analyses and 3 (3.4%) re-analyses. The median (interquartile range) Altmetric Attention Scores were 5.9 (1.3—22.2) for re-use and 2.8 (0.3—12.3) for controls (p?=?0.14). No statistical difference was found on any of the components of in the Altmetric Attention Score. The median (interquartile range) numbers of citations were 3 (1—8) for reuses and 4 (1 – 11.5) for controls (p?=?0.30). Only 6/89 re-uses (6.7%) were cited in a policy source.
Using all available re-uses of RCT data to date from major data repositories, we were not able to demonstrate that re-uses attracted more attention than a matched sample of studies published in the same journals. Small average differences are still possible, as the sample size was limited. However matching choices have some limitations so results should be interpreted very cautiously. Also, citations by policy sources for re-uses were rare.