Open Access Open Badges Study protocol

Practice network-based care management for patients with type 2 diabetes and multiple comorbidities (GEDIMAplus): study protocol for a randomized controlled trial

Kayvan Bozorgmehr1*, Joachim Szecsenyi1, Dominik Ose1, Werner Besier2, Manfred Mayer2, Johannes Krisam3, Christian O Jacke4, Hans-Joachim Salize4, Ralf Brandner5, Sandra Schmitt5, Marion Kiel1, Martina Kamradt1 and Tobias Freund1

Author Affiliations

1 Department of General Practice and Health Services Research, University Hospital Heidelberg, Voßstrasse 2, Gebäude 37, Heidelberg 69115, Germany

2 Genossenschaft Gesundheitsprojekt Mannheim e G, Liebfrauenstrasse 21, Mannheim 68259, Germany

3 Department for Medical Biometry, Institute for Medical Biometry and Informatics, University Hospital Heidelberg, Im Neuenheimer Feld 305, Heidelberg 69120, Germany

4 Central Institute of Mental Health (ZI), Medical Faculty Mannheim, Heidelberg University, D6-5, Mannheim 69159, Germany

5 InterComponentWare AG, Altrottstraße 31, Walldorf 69190, Germany

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Trials 2014, 15:243  doi:10.1186/1745-6215-15-243

Published: 21 June 2014



Care management interventions in the German health-care system have been evaluated with promising results, but further research is necessary to explore their full potential in the context of multi-morbidity. Our aim in this trial is to assess the efficacy of a primary care practice network–based care management intervention in improving self-care behaviour among patients with type 2 diabetes mellitus and multiple co-occurring chronic conditions.


The study is designed as a prospective, 18-month, multicentre, investigator-blinded, two-arm, open-label, individual-level, randomized parallel-group superiority trial. We will enrol 582 patients with type 2 diabetes mellitus and at least two severe chronic conditions and one informal caregiver per patient. Data will be collected at baseline (T0), at the primary endpoint after 9 months (T1) and at follow-up after 18 months (T2). The primary outcome will be the differences between the intervention and control groups in changes of diabetes-related self-care behaviours from baseline to T1 using a German version of the revised Summary of Diabetes Self-Care Activities (SDSCA-G). The secondary outcomes will be the differences between the intervention and control groups in: changes in scores on the SDSCA-G subscales, glycosylated haemoglobin A level, health-related quality of life, self-efficacy, differences in (severe) symptomatic hypoglycaemia, cost-effectiveness and financial family burden. The intervention will be delivered by trained health-care assistants as an add-on to usual care and will consist of three main elements: (1) three home visits, including structured assessment of medical and social needs; (2) 24 structured telephone monitoring contacts; and (3) self-monitoring of blood glucose levels after T1 in 3-month intervals. The control group will receive usual care. The confirmatory primary analysis will be performed following the intention-to-treat (ITT) principle. The efficacy of the intervention will be quantified using two-level linear regression stratified by type of medical treatment adjusted for baseline values on the SDSCA-G. Secondary analyses will be performed according to the ITT principle. In health economic evaluations, we will estimate the incremental cost-effectiveness ratios.


We hope that the results of this study will provide insights into the efficacy of practice network–based care management among patients with complex health-care needs.

Trial registration

Current Controlled Trials ISRCTN 83908315 (ISRCTN assigned 25 February 2014).

Care management; Chronic care; Diabetes; Multi-morbidity; Primary care; Self-care