Assessing water and health insecurity in informal settlements: Bringing Europe's invisible, marginalized Roma communities into focus. A systematic scoping review

Vulnerable groups at the margins of societies in Europe, such as Roma people, often live in unregulated housing, where they cannot access safe drinking water, sanitation and waste management. The invisibility of these groups and inaccessibility of reliable, up-to-date information complicates understanding of service gaps, related health risks, and the potential for assistance through targeted interventions. We conducted a systematic scoping review to capture the state of the art of water and health insecurity assessment in Roma communities in Europe. The methodological quality of the included studies was assessed using mixed methods appraisal tool (MMAT) version 2018. Results showed a body of research reliant on disparate assessment methods, although most studies combined multiple methods. The studies often focused on narrow issues, neglecting a wider systems approach, or neglected the community entry, participation, and synthesis steps needed to adapt existing research approaches to more challenging settings and contexts. Some methods - though vital to understand water and health insecurity - were underrepresented. These included water quality testing, period prevalence of self-reported symptoms, and longitudinal approaches. Studies also failed to use the full potential of methods applied, for example using geospatial data for risk mapping risks or spatial analysis. Most studies fell short in providing detailed setting descriptions and ethical considerations, risks entailed, and strategies to counteract those. We propose alternatives to more systematically address data gaps and implement state-of-the-art assessment methods that better match the water and health service challenges posed by communities on the margins of society.