SLIMMER: a randomised controlled trial of diabetes prevention in Dutch primary health care: design and methods for process, effect, and economic evaluation

Abstract

BackgroundImplementation of interventions in real-life settings requires a comprehensive evaluation approach. The aim of this article is to describe the evaluation design of the SLIMMER diabetes prevention intervention in a Dutch real-life setting.Methods/DesignThe SLIMMER study is a randomised, controlled intervention study including subjects aged 40 through 70 years with impaired fasting glucose or high risk of diabetes. The 10-month SLIMMER intervention involves a dietary and physical activity intervention, including case management and a maintenance programme. The control group receives usual health care and written information about a healthy lifestyle. A logic model of change is composed to link intervention activities with intervention outcomes in a logical order. Primary outcome is fasting insulin. Measurements are performed at baseline and after 12 and 18 months and cover quality of life, cardio-metabolic risk factors (e.g. glucose tolerance, serum lipids, body fatness, and blood pressure), eating and physical activity behaviour, and behavioural determinants. A process evaluation gives insight in how the intervention was delivered and received by participants and health care professionals. The economic evaluation consists of a cost-effectiveness analysis and a cost-utility analysis. Costs are assessed from both a societal and health care perspective.DiscussionThis study is expected to provide insight in the effectiveness, including its cost-effectiveness, and delivery of the SLIMMER diabetes prevention intervention conducted in Dutch primary health care. Results of this study provide valuable information for primary health care professionals, researchers, and policy makers.Trial registrationThe SLIMMER study is registered with ClinicalTrials.gov (NCT02094911) since March 19, 2014.

Present and future of nutrition guidance : lifestyle advice in primary care

“…Duijzer et al reported on the the feasibility and potential impact of the SLIMMER pilot study (165). The design and methods for the process, effect, and economic evaluation of SLIMMER were published in 2014 (166). Using the intervention mapping protocol, Elsman et al developed a maintenance programme for the SLIMMER diabetes prevention intervention (167).…”

Community based diabetes prevention programme in older adults in a Greek rural area

“…Improved nutritional habits, especially the significant decrease of daily energy, saturated fat and increase of dietary fiber, produced beneficial effects, like reduction in hypertension and hyperlipidemia, as other trials and community-based programmes have shown. [13][14][15][16][17][18][19][20][21][22][23][24]36 The non-significant decrease in other metabolic factors could be attributed to the fact that their baseline levels were normal. The high quantity of fat consumption was explained because of the extremely high consumption of olive oil and nuts, the basic characteristics of the Mediterranean diet.…”

“…In all studies, more women than men attended the programmes. [18][19][20][21][22][23][33][34][35] In our programme, men refused to participate. This suggests that a range of different approaches may be needed to engage people who are at risk for diabetes and emphasis should therefore be put on indentifying the barriers to male attendance.…”

“…Small community-based programmes have reported some success in modifying surrogate markers for diabetes through lifestyle intervention. [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] These trials and small community-based programmes primarily enrolled middle-aged participants. Only in the U.S. Diabetes prevention program (DPP), which is the largest trial to date, 20% of the participants were aged ≥60 years at enrollment.…”

Type 2 Diabetes Prevention Programs; How Far are we?

“…Realistic costeffectiveness studies of lifestyle interventions in people at risk for lifestyle-related diseases, addressing 'real-world' implementation, are also needed [21,104,105].…”