It is predicted that emergency response to critical incident events will likely increase in the coming decades, as society faces unique and dynamic challenges (e.g., pandemics, migrant crises, terrorism). As such, it is necessary to breakdown, identify and evaluate the unique barriers associated with decision-making in the context of critical incident response. Current research has often framed the factors that influence critical incident-related decision-making in respect to independent singular sociological and psychological characteristics. The aim of this study was to synthesise the bibliographic characteristics of the research and present a holistic narrative analysis of the multi-layered factors associated with decision-making. The systematic synthesis of evidence also facilitated a critical appraisal of the quality and distribution of evidence across macro-, meso-, and micro- levels. Results suggested that research was moderately heterogeneous, as the synthesis of evidence captured diverse narrative factors. However, eligible research remained sparse and often focused on singular factors. Further, micro-centric characteristics (e.g., cognitive-related factors) were not well represented. Research primarily focused toward intermediate meso-level characteristics, capturing factors such as ‘interoperability’ and ‘organisation policy and procedure’ as critical challenges to decision-making. Six key narratives were also identified and discussed. Both the quality appraisal and narrative findings suggested that research should seek opportunities to experimentally assess, evaluate and validate decision-making. In practice, whilst this has in the past appeared ethically and practically problematic, advances in technology, research and analysis have allowed high-fidelity simulation experimentation to recreate critical incident events.