Type 2 diabetes in Indigenous populations: quality of intervention research over 20 years

Background: A robust evidence base is needed to reduce the disproportionately high rates of diabetes-related mortality and complications among Indigenous peoples.

Objective: This study aimed to evaluate the quantity and methodological quality of published intervention research on Type 2 and gestational diabetes in the Indigenous populations of Australia, Canada, New Zealand, and the United States from 1989 to 2008. A robust evidence base is needed to reduce the disproportionately high rates of diabetes-related mortality and complications among Indigenous peoples.

Methods: Systematic searches of Medline, Embase, and EBM Reviews identified publications focused on Type 2 or gestational diabetes in Indigenous peoples published between 1 January 1989 and 31 December 2008. Total publication number and proportion of research involving interventions over time were examined. The quality of intervention studies was evaluated using Cochrane's Effective Practice and Organisation of Care (EPOC) criteria.

Results: Total publication number increased significantly over the 20 years (p<0.004). Research was predominantly descriptive (87%), with the proportion of research involving interventions increasing from 3% in 1989-1993 to 12% in 2003-2008 (χ(2)=12.42, df=3, p=0.006). However, only 25% (95%CI: 9-41%) of intervention studies met the EPOC methodological quality criteria; other studies lacked sufficient controls or measurements over time.

Conclusions: Increases in the amount of high-quality intervention research for prevention and treatment of Type 2 and gestational diabetes among Indigenous populations of these countries are needed.