Obtaining evidence base for the development of Feel4Diabetes intervention to prevent type 2 diabetes - a narrative literature review.

Background: Feel4Diabetes was a school and community based intervention aiming to promote healthy lifestyle and tackle obesity for the prevention of type 2 diabetes among families in 6 European countries. We conducted this literature review in order to guide the development of evidence-based implementation of the Feel4Diabetes intervention. We focused on type 2 diabetes prevention strategies, including all the phases from risk identification to implementation and maintenance. Special focus was given to prevention among vulnerable groups and people under 45 years.

Methods: Scientific and grey literature published between January 2000 and January 2015 was searched for relevant studies using electronic databases. To present the literature review findings in a systematic way, we used the Reach, Effectiveness, Adoption, Implementation, and Maintenance (RE-AIM) framework. A complementary literature search from February 2015 to December 2018 was also conducted.

Results: The initial review included 27 studies with a follow-up ≥12 months and 9 studies with a follow-up ≥6 months and with a participant mean age < 45 years. We found out that interventions should be targeted at people at risk to improve recruiting and intervention effectiveness. Screening questionnaires (primarily Finnish Diabetes Risk Score FINDRISC) and blood glucose measurement can both be used for screening; the method does not appear to affect intervention effectiveness. Screening and recruitment is time-consuming, especially when targeting lower socioeconomic status and age under 45 years. The intervention intensity is more important for effectiveness than the mode of delivery. Moderate changes in several lifestyle habits lead to good intervention results. A minimum of 3-year follow-up seemed to be required to show a reduction in diabetes risk in high-risk individuals. In participants < 45 years, the achieved results in outcomes were less pronounced. The complementary review included 12 studies, with similar results regarding intervention targets and delivery modes, as well as clinical significance.

Conclusion: This narrative review highlighted several important aspects that subsequently guided the development of the Feel4Diabetes high-risk intervention. Research on diabetes prevention interventions targeted at younger adults or vulnerable population groups is still relatively scarce. Feel4Diabetes is a good example of a project aiming to fill this research gap.

Trial Registration: clinicaltrials.gov NCT02393872, registered 20th March 2015.