Evaluating Overton and Altmetric as tools for tracking healthcare research use and impact on policy and practice: a descriptive study.

Background: Since 2010, the UK's National Institute for Health and Care Research has funded a policy research unit (PRU) focused on maternal and neonatal health, with a remit to build an evidence base for policy and clinical practice in this field. We explored the usefulness of the platforms Overton and Altmetric as tools to gain insight into the use of PRU research evidence in policy and practice. Methods: We searched Overton and Altmetric using article DOIs to identify citations of PRU-funded articles in policy documents and clinical guidelines. We excluded citations of the research in lists of excluded evidence, academic journal articles, and unverifiable citations. To obtain a count of unique citing documents for each article, we merged multiple editions/versions, translations, and duplicates of the same document. We calculated latency from article publication date to citation date, and citation distribution over time. We also developed descriptive case studies to explore how the citing policy documents used highly-cited research evidence. Results: The 110 published articles reporting research funded by the PRU received 134 unique policy document and clinical guideline citations; 43/110 articles (39%) were cited in at least one document. Most citing documents were authored by organisations based in the UK (52/134) and other high-income countries. Intergovernmental organisations accounted for around 15% of citations (20/134). The median time from article publication to citation was 183 weeks (range 0.4-575 weeks). Citation contexts varied; use of the evidence in citing documents included provision of general background information, detailed summaries of findings, and support/rationale for specific clinical recommendations. Conclusions: Overton and Altmetric are useful tools for identifying and exploring the use of research evidence in healthcare policy and clinical guidance. However, citation analysis alone cannot provide the complete picture. The delay between evidence publication and use in policy warrants further investigation.