What are the methodological characteristics of evidence and gap maps? A systematic review and evidence and gap map

Introduction

Clarity on the characteristics of methods used to produce evidence and gap maps (EGMs) will highlight areas where method development is needed to ensure these increasingly produced tools are made following best practice to assure their quality and utility. This paper aims to describe the range, nature and variability of key methodological characteristics of studies publishing EGMs.

Methods

We followed a protocol, written a-prior and informed by PRISMA and MECCIR guidelines for undertaking systematic reviews. We searched nine data bases, from 2010, for studies across any discipline that included details of their methods used to produce an EGM. Search results were screened by two reviewers independently and the subsequent data was extracted and managed according to predefined criteria. We mapped these together with the year of publication and the area of research as the two primary dimensions. We followed established methods for mapping the evidence, including the process of developing the map framework and the filters for our interactive map. We sought input and involvement from stakeholders during this process.

Results

We found 145 studies from nine distinct research areas, with health research accounting for 67%. There were 11 map designs found, of these bubble plots were the most common design, before 2019, since then it has been a matrix map design. Stakeholders were involved in 47.7% of studies, 48.35% of studies stated finding gaps was an aim of their work, 42% reported publishing or registering a protocol and only 9.39% of studies mentioned a plan to update their evidence maps/EGMs.

Discussion/Conclusion

Key areas of methodological development relate to: the involvement of stakeholders, the conceptualization of gaps and the practices for updating maps. The issues of ambiguity in terminology, the flexibility of visualizations of the data and the lack of reporting detail were other aspects that needs further consideration in studies producing an EGM.