Evaluating the homeless population access to mental health services with a validated questionnaire: strengths and challenges.

This article presents the methodological path for developing a structured survey to collect primary data on the vulnerable population, in this case, focused on measuring the people experiencing homelessness (PEH) access to the Psychosocial Care Network (RAPS). The validation process was conducted in Belo Horizonte, Minas Gerais, Brazil, in 2024, and the methodology followed three stages: 1) questions development and definition of the scales used; 2) theoretical and empirical validity tests; 3) quality and reliability tests: completeness and consistency. An questionnaire was assembled with 40 questions divided into three sections: i) sociodemographic characteristics, ii) health issues and patterns of alcohol/other drug use, and iii) experiences of access to mental health services. The final product was a concise research questionnaire directed at the research objectives, language accessible, and culturally adapted to the target population. The questionnaire can be relevant to the data quality and collection of vulnerable populations, considering it can be used for other similar assessments, it could be adapted to specific goals, and the same validation process can be followed to improve data quality standards. The process can qualify discussions on the reality of PEH with the development of focused public policies.