Aims
Family interventions are increasingly recognized as important in the care of people with diabetes. The aim of this study was to synthesize the existing literature on family interventions among adults with Type 1 and Type 2 diabetes and to determine the degree to which they were family centred.

Methods
The literature search was carried out in four databases (Scopus, CINAHL, PsycINFO and ERIC). Two reviewers independently screened the search results. Only English-language articles about interventions on education, care and/or support of adult individuals with diabetes involving the participation of both the individual with diabetes and at least one family member were included.

Results
From an initial 1480 citations, 10 reports were included. The intervention studies varied considerably in terms of design and population. The family dimension generally represented a modest part of the interventions: Two interventions applied a family-relevant theoretical framework. Disease knowledge and lifestyle changes were more prevalent intervention themes than family issues. Biological and behavioural outcomes were most prevalent, whereas psychosocial and family outcomes were used in six of the studies.

Conclusions
The number of trials and statistically significant results in family interventions targeting adults with diabetes is limited. Because of inhomogeneity, it is difficult to come to a conclusion on effective approaches in family interventions. The interventions are inconsistent with regard to theoretical framework, intervention themes and measured outcomes. However, psychosocial and familial dimensions seem sensitive to family-based interventions. From development to evaluation, the family dimension needs to be included to prove the specific effect of family interventions.