Background: High-quality evidence is essential to inform international development programmes. Despite this, evidence of what works for development in low-and-middle income countries is relatively scarce. To address this, Sightsavers are developing evidence gap maps (EGMs) using the International Initiative for Impact Evaluation methodology. EGMs summarise, appraise and present evidence from systematic reviews in a user-friendly, visual format. This presentation will focus on the benefits and methods used to construct three EGMs developed by us to date.
Methods: Following a comprehensive search of the literature, we sifted, and extracted data from all relevant reviews. Critical appraisal was conducted by two independent reviewers using the Supported Use of Research Evidence checklist. A summary of quality assessment was shared with the authors for comment. The tool gives reviews an overall rating of high, medium or low confidence based on the methodological quality assessment. This is indicated on the EGM using a traffic light system; green, orange and red bubbles represent high, medium and low levels of confidence in the review conclusions respectively. Each review was represented by a coloured bubble and placed in the cell corresponding to the relevant intervention along the x-axis and the strength of evidence along the y-axis. Evidence of each review was categorised as strong, inconclusive or weak based on the findings and conclusions reported by review authors.
Conclusions: EGMs help to identify methodological strengths and weaknesses of existing reviews. They encourage more systematic approaches to synthesise evidence, identify thematic areas where few/no reviews are available and suggest questions for future systematic reviews. The process of developing EGMs is dependent on the number, thematic focus and quality of systematic reviews available.