AdMiRE study: Development and validation of a WHO-aligned tool to assess healthcare access and antibiotic use among migrant populations in Europe—a multicountry Delphi and psychometric study on behalf of ESGITM group

Objectives Migrants and refugees face a high burden of infections caused by multidrug-resistant bacteria but frequently encounter structural barriers to healthcare and appropriate antibiotic treatment. This multicountry study applied a structured Delphi process to develop a standardized survey that systematically assesses healthcare access and barriers to appropriate antibiotic use among migrant and refugee populations in Europe. Methods A multicountry Delphi consensus study was conducted with two different panels of experts including 64 experts from 12 European countries, from academia, clinical practice, nongovernmental organization, and migrant communities, to design and validate a survey on healthcare access and antibiotic use. Content validity was assessed using Item- and Scale-level Content Validity Indices (I-CVI and S-CVI/Ave) and the interquartile range. The finalized questionnaire was pilot-tested among 183 migrants, evaluating internal consistency (Cronbach’s α; KR-20), temporal stability (intraclass correlation coefficient), inter-rater reliability (κ), and construct validity via exploratory factor analysis. Results Fifteen of 16 experts (94%) completed both Delphi rounds. The S-CVI/Ave improved from 0.94 to 0.95, and the mean interquartile range decreased from 0.38 to 0.02, indicating strengthened content validity and consensus. External validation confirmed excellent agreement (S-CVI/Ave = 0.96). Psychometric testing demonstrated good reliability (Cronbach’s α = 0.82–0.91; KR-20 = 0.79), substantial inter-rater agreement (κ = 0.72), and robust construct validity (KMO = 0.84; Bartlett’s test p <0.001). Conclusions The AdMiRE questionnaire is a reliable and methodologically robust tool for assessing healthcare access and antibiotic use among migrants and refugees in Europe. This validated instrument provides a standardized framework for generating comparable data to inform policies, strengthen antimicrobial stewardship, and promote equitable access to care across migrants.