Evidence on cataract in low- and middle-income countries: an updated review of reviews using the evidence gap maps approach

Abstract

In 2014, Sightsavers developed the first evidence gap map (EGM) to assess the extent and quality of review-level evidence on cataract relevant to low-and middle-income countries. The EGM identified 52 studies across five broad themes. This paper reports the update of the EGM conducted in 2021 and changes to the extent and quality of the evidence base. We updated the EGM using the exact process conducted to develop the original. Searches were run to 14 September 2021, and two independent reviewers selected eligible studies, critically appraised them and extracted data using the Supporting the Use of Research Evidence checklist. A summary quality assessment was shared with the authors for comments. Forty-six new reviews were identified, and the EGM now includes 98 reviews. The new reviews predominantly focus on treatment and risk factors. The overall methodological quality was found to be improved, with 13/46 reporting high confidence in findings. EGMs remain a useful tool for policy-makers to make informed decisions and periodic updates are important to assess changes and to refine the focus for future research. The EGM highlights significant disparity in the topics addressed by reviews, with health system interventions particularly neglected.

Protective factors for adverse childhood experiences: Scoping review and evidence gap map.

“…EGMs share some qualities with other approaches for synthesis and mapping evidence (e.g., evidence maps, scoping studies, systematic maps, rapid evidence assessments, and systematic reviews); however, EGMs bring together various features of other approaches that set them apart. EGMs were originally designed to evaluate interventions, but they have been applied more broadly to examine nonintervention research (Bragge et al, 2011; Jolley et al, 2022; Rodrigues-Machado et al, 2022). Overall, EGMs offer a visual depiction of existing evidence to highlight critical gaps in existing knowledge areas, augmenting traditional scoping reviews (Snilstveit et al, 2016).…”