Mapping the evolving definitions of translational research

Abstract

Objective: Systematic review and analysis of definitions of translational research.

Materials and methods: The final corpus was comprised of 33 papers, each read by at least 2 reviewers. Definitions were mapped to a common set of research processes for presentation and analysis. Influence of papers and definitions was further evaluated using citation analysis and agglomerative clustering.

Results: All definitions were mapped to common research processes, revealing most common labels for each process. Agglomerative clustering revealed 3 broad families of definitions. Citation analysis showed that the originating paper of each family has been cited ~10 times more than any other member.

Discussion: Although there is little agreement between definitions, we were able to identify an emerging consensus 5-phase (T0-T4) definition for translational research. T1 involves processes that bring ideas from basic research through early testing in humans. T2 involves the establishment of effectiveness in humans and clinical guidelines. T3 primarily focuses on implementation and dissemination research while T4 focuses on outcomes and effectiveness in populations. T0 involves research such as genome-wide association studies which wrap back around to basic research.

Conclusion: We used systematic review and analysis to identify emerging consensus between definitions of translational research phases.

Keywords: Biomedical research/trends; Clinical trials as topic; Terminology as topic; Translational medical research; Translational medical research/trends.

Fig. 1

Systematic search and filtering flow chart. Bibliographic search in 4 sources, deduplication, manual curation, and dual reviewer filtering produced a final corpus of 33 papers.

Fig. 2

Primary review results with consensus, clustering, and total citation information. The center of the figure shows the results of primary definition labeling. Blank cells indicate that the particular paper did not mention that research activity. Target development includes 3 named activities that were categorized the same by all papers (target validation, lead optimization, and lead development). The top of the figure shows a dendrogram representing the results of agglomerative clustering on the activity categories, resulting in 3 main definition families and a set of outliers (the “Other” grouping and Blumberg on the right), and also defines the order of papers for presentation. The far right side of the figure includes a consensus categorization and graph showing the frequency of assignment of each process to each T-phase as a fraction of all papers in the corpus. Early clinical trial phases are labeled as mixed T2**. Although historic majority labeling is T1, since 2010 the predominant and emerging consensus label for these processes is T2. Citation counts for each paper are included below as a bar graph overlaid with the actual citation count for each paper.

Fig. 3

Directed citation network. Nodes represent papers in the corpus. Directed edges represent a citation of the target by the source. Size and color of each node reflects the number of times that paper was cited by other papers in the corpus (red, large—high citation count; yellow, small—low citation count; and green, tiny—no citation count). Height of a node corresponds to year of first availability either in print or online.