Recruiting underrepresented populations for surveys: the case of people with schizophrenia and coexisting diabetes

Aim: To describe the challenges and strategies involved in recruiting adults to a cross-sectional survey study on psychosocial health and support, with individuals with schizophrenia and type 2 diabetes as the case. Materials and methods: This descriptive study tracked the recruitment process for a Danish survey study in a register, systematically synthesising all relevant information. This included details on how eligible patients were identified and invited to the study and their reasons for declining. Two recruitment strategies were employed: (1) Recruitment via mental health professionals in psychiatric outpatient clinics in Region Zealand, and (2) Recruitment via phone calls to eligible patients. Descriptive analyses of the recruitment data were conducted. Results: Three challenges were identified and described: (1) Challenges in identifying eligible patients, (2) Challenges in having mental health professionals to recruit participants, and (3) Patients’ inability to complete the questionnaire. The first two challenges were addressed through practical approaches: (1) Identifying eligible patients via electronic health records and medication types, and (2) Directly inviting patients via phone calls from a member of the research team. No additional initiatives were implemented to address the third challenge. Approximately 15% of all eligible patients declined to participate, indicating a high willingness to participate among the remaining individuals. Conclusions: Exploring various challenges was crucial for understanding the difficulties in recruiting this population, initiating new approaches to address these challenges, and recognising the high willingness to participate. Greater emphasis should be placed on patients’ rights to make their own decisions regarding participation in research.