Challenges associated with recruiting multigenerational, multicultural families into a randomised controlled trial: Balancing feasibility with validity

Abstract Recruitment of participants into research studies has become an increasingly difficult task with justifiable criticisms of representativeness of samples. The difficulties of recruitment are exacerbated when the study is longitudinal, requires multiple members from one family and incorporates people from non-dominant ethnic backgrounds. This paper describes a complex trial's recruitment process. Family groups were required for a longitudinal randomised controlled trial investigating links between health and dietary behaviours with an aim to improve primary prevention health messages and initiatives. To be representative of the multi-ethnic composition of the South Australian population, families from three of South Australia's largest ethnic backgrounds were invited to participate. Of these, only families with participating members spanning three generations were enrolled, so that links between health and lifestyle behaviours with possible generational ties could be investigated. Immense difficulties were faced during recruitment and significant modifications to the initial recruitment plan were necessary to enable the enrolment of 96 families. Challenges faced included lack of response to recruitment materials displaying complex eligibility criteria and different response outcomes from different communities. Solutions implemented included simplifying materials and tailoring recruitment activities to specific communities' needs. This trial's recruitment journey will be used as a case study to highlight the practicalities of recruiting for complex trials. Recommendations will be provided for future researchers seeking to recruit multigenerational, multi-ethnic families into the same study, along with issues to consider regarding the implications of the recruitment journey on the integrity of a complex trial and the potential threats to internal validity.