Culturally tailored lifestyle interventions for the prevention and management of type 2 diabetes in adults of Black African ancestry: a systematic review of tailoring methods and their effectiveness

Objective: To evaluate the cultural tailoring methods used in type 2 diabetes (T2D), prevention and management interventions for populations of Black African ancestry and to examine their effectiveness on measures of glycaemia. Design: Three databases were searched in October 2020; eligible studies used a randomised controlled trial (RCT) design to evaluate the effectiveness of culturally tailored lifestyle interventions compared with usual care for the prevention or management of T2D in adults of Black African ancestry. Cultural tailoring methods were evaluated using the Facilitator-Location-Language-Messaging (FiLLM) framework, whereby facilitator refers to delivery by individuals from the target community, language focuses on using native language or language appropriate to literacy levels, location refers to delivery in meaningful settings, and messaging is tailoring with relevant content and modes of delivery. Results: Sixteen RCT were identified, all from USA. The mean age of participants was 55 years, majority female. Six of fifteen RCT reported significant improvements in glycated haemoglobin (HbA1c) at 6 and 8 months; one, in prediabetes, reported significantly improved fasting plasma glucose. Diabetes knowledge improvement (5/7 studies) was associated with HbA1c improvement. The majority tailored to location (12/16), facilitators (11/16), messaging (9/16) and language (6/16) domains of FiLLM. Those with ethnically matched facilitators and those which tailored to more than one domain showed the greatest HbA1C benefits. Conclusion: This evidence supports the effectiveness of culturally tailored lifestyle interventions for T2D management in populations of Black African ancestry, with further RCT needed to evaluate interventions for T2D prevention and for communities outside of the USA.