Diabetes und Herzinfarkt

Studie zur Entwicklung und Evaluation einer Entscheidungshilfe zur Vorbeugung von Herzinfarkt bei Typ 2 Diabetes



This project aims at implementing an education and counselling programme on the prevention of myocardial infarction for patients with type 2 diabetes that integrates the principles of evidence-based patient information and shared decision making. The programme aims at empowering the individual patient to define and to negotiate a hierarchy of treatment goals and preventive interventions. The programme will be a complex intervention comprising multiple active components: 1) A decision aid booklet that provides the relevant evidence-based information has been developed and successfully pilot tested in a previous project; 2) a counselling strategy for patients will be developed, aimed at individualising that information and integrating it into shared decision-making; 3) a training programme will be developed, aimed at strengthening the diabetes educators’ and physicians’ shared decision-making skills. The final product will also be a prototype of a counselling module on shared decision making in diabetes care, which can be integrated in any diabetes education programme, and which can be adopted and adjusted for other medical decisions in specialised diabetes centres or the primary health care level.


Cardiovascular disease is the predominant life threatening complication associated with type 2 diabetes. An array of behavioural directives is imposed on persons with type 2 diabetes, such as quitting smoking, increasing exercise, normalising weight, and adhering to monitoring, dietary and medication prescriptions. Evidence on effectiveness of these measures is varying and some may even do more harm than good [1]. Patients frequently feel demotivated and overloaded by the plethora of medical prescriptions contributing to poor long-term adherence to the most effective preventive interventions such as control of blood pressure [2] and use of statins [3].

Informed Shared Decision Making for people with diabetes

Lack of patient involvement in decision making has been suggested as one reason for limited treatment success [4, 5]. The concept of shared decision making (SDM) aim at supporting patients to make evidence-based informed choices together with their physicians [6]. There are a lot of concepts of decision making, such as paternalism, when physicians make the decision without involving their patients, or autonomous informed decision making, when patients are empowered to make autonomous decisions just by being provided with high quality information. SDM involves patients actively in decision making. Involvement of patients improves knowledge [4, 5]. And, better informed patients involve themselves more in their own medical decisions [7]. As a central criterion in the concept of SDM information has to be evidence-based, complete and unbiased [4-6, 8]. This is underlined by the term informed shared decision making (ISDM).

Decision Aids for people with diabetes

Patient decision aids (DAs) are tools to facilitate SDM [9, 10]. They typically provide information on the health problem and available treatment options. DAs are designed to help people make specific and deliberative choices among options by providing information about the options and outcomes that are relevant to a person’s health status (e.g. estimates of probable treatment effects) and by supporting patients to clarify and communicate the personal value they associate with different features of the options (e.g. exercises and strategies to structure decision-making).

The current Ottawa Inventory [11] (lastly updated 8/2010) lists five DAs specifically designed for people with type 2 diabetes [12-16]. We have perpetually updated previous systematic literature searches, [17] using PubMed, EMBASE, CINAHL, PsycINFO, and PSYNDEXplus; additional DAs were not identified. One additional DA was identified by personal contact [18]. One publication about a diabetes DA, which is still under evaluation, was identified, but is currently not available [19]. In a previous article we summarised the characteristics of the five currently available DAs [20]. We concluded that no patient DA is currently available, providing the whole package of evidence-based information on primary prevention of myocardial infarction in type 2 diabetes, necessary for IDM. In a previous project we have developed an evidence-based DA for primary prevention of MI in type 2 diabetes [12].

Methodological Issues

Different tools have been developed to facilitate critical appraisal of DAs. The International Patient Decision Aids Standards (IPDAS) Collaboration established internationally consented quality criteria [21]. Our research group developed MATRIX, a guide designed to make development and evaluation of DAs more transparent [22, 23].

In diabetes care, single interventions (e.g. a single drug) coexist with complex interventions (e.g. treatment regimens, patient education and patient DAs). Complex interventions typically comprise a number of components that may act interdependently and seem essential to their proper functioning [24].

The U.K. Medical Research Council (UKMRC) proposed guidance on the development, evaluation and implementation of complex interventions [25]. Four phases of a development and evaluation process were defined.

Preliminary data

The DA, developed by our group [12], targets lifestyle changes and drug interventions recommended for primary prevention of MI. It is written in German [25], an English translation is also available [26]. The DA is aimed at being used by patients to prepare them for consultations with their diabetes educator and/or their general practitioner. Objective is that patients understand and clarify personal importance of outcomes and probabilities of their occurrence, and participate in decision-making actively. We published the theoretical concept of the DA, component modelling and preliminary qualitative evaluation of this DA in a recent paper [12]. The methods followed the UKMRC guidance [24]. The evaluation with target group patients suggested that most parts of the DA were comprehensible and that information needs were mainly satisfied.

Methods of procedure

The core component of the planned ISDMP is the previously developed DA [12]. The planned project comprises three methodological phases following the UKMRC guidance [24].

In the first phase, additional ISDMP-components will be developed that are necessary for a successful implementation of the DA. In the second phase, efficacy of the ISDMP will be evaluated in a short-term randomised controlled trial (RCT). In the third phase, implementation effectiveness of this programme will be evaluated over 12 months within a cluster randomised controlled trial (RCT).

Phase 1: Development of the ISDM-Programme and of instruments for evaluation

Additional components, necessary for a successful implementation of the DA in terms of ISDM, will be developed: a counselling module for groups (strategy and media) and a corresponding educational module, addressing the providers of the counselling (specialised nurses/physicians assistants.

Development of these communication components will include sequential piloting and Pre-testing, using various qualitative methods. Therefore a comprehension test and a guideline for semi-structured interviews will be developed.

Development of instruments for evaluation

The educational success of the counselling will be evaluated using a comprehension test. I.e. revision of the modules will be undertaken based on those test results. In addition, the comprehension test will be a basic component of multidimensional outcome measures used in phases 2 and 3 of this project.

The educational success of the educational module will be evaluated with semi-structured interviews. An interview guideline will be developed.

Development and evaluation of the counselling module

The counselling module aims  to supplement the DA so that the intervention meets all criteria of an SDM-process [27]. Emphasis is laid on all interactive and negotiating skills to involve the patients in decision-making and to reassure an intensive and unbiased information process. I.e.:

1)       Patients will be motivated to involve themselves by the statement of equipoise (i.e., saying that from the medical point of view there is no one true way to go)

2)       Patients will be asked whether and how they understood the evidence based patient information provided by the DA, and

3)       Individualized exploration of patient values and preferences will be performed

A curriculum and specific media will be developed, corresponding to the already existing DA. Moreover a catalogue of questions based on MAPPIN`SDM [28, 29] will be used. The counselling will take 45 minutes.

Evaluation of the counselling module will be conducted at the Diabetes Hospital of Asklepios in Hamburg Rissen.

According to the counselling module, a control intervention will be developed and evaluated to conduct an RCT in the next step (phase 2).

Development of the provider training module

The training aims at enabling unbiased communication on myocardial risk and prevention between the providers of the counselling and the patients, according to the criteria of IDM/SDM. The providers should demonstrate competence in:

1)       Explaining and individualising the relevant contents of the DA

2)       Presenting numerical information to patients in a comprehensible and unbiased manner

3)       Actively involving the patient into the information-and decision making process [27].

To address competence 1, specific media will be developed, corresponding to the already existing DA. To address aims 2 and 3, the doktormit training curriculum [28, 30, 31] for physicians will be adjusted to the needs of the project and the target group. This program has been developed within the context of numerous research projects on shared decision-making (SDM) in several Hamburg-based research groups [32-35].

The evaluation of the provider training will be conducted at the diabetes hospital of Asklepios in Hamburg Rissen and at the diabetes hospital of Sana in Oldenburg.

Moreover a provider training for the control group will be developed and evaluated on the lines of the provider training for the intervention group.

Phase 2: Evaluation of the ISDM programme in a randomised controlled trial

The efficacy of the ISDMP will be evaluated in a randomised controlled trial (RCT). The study will be conducted at the diabetes out-patient clinic of the University Hospital Jena, Germany.

Outcome data on the primary endpoint will be used to specify sample size calculation for the subsequent effectiveness trial (phase 3).

The CONSORT-statement will be followed [36].

Provider training

Initially, the provider training will be given to four diabetes educators of the diabetes out-patient clinic of the University Hospital Jena.

Eligibility and recruitment

Patients are eligible with type 2 diabetes, aged between 45 and 69 years, with no previous diagnosis of ischemic heart disease (ICD I20-I25) or stroke (ICD I63), enrolled in the DMP for type 2 diabetes and if they participate in the diabetes DMP education modules. Patients are eligible with HbA1c-values between 6 and 9%. This range of values is sensitive to patient participation in decision making, regarding micro-vascular prevention.

Patients will be excluded if they have cognitive disorders, proliferative retinopathy, chronic kidney disease stage three or higher (KDOQI), addiction to alcohol, and metastatic cancer.

Recruitment will be conducted by members of the diabetes outpatient clinic of the University of Jena.

Standardised participant information will be given to eligible patients and standardised forms will be used to document informed consent for study participation. After written informed consent is achieved, baseline data will be collected. Following completion of the study, patients will be informed about study results.

Study procedure

Eligible patients will be asked to read and work through the DA (control intervention respectively), before the group counselling sessions will be provided. Providers will be instructed to restrict the provided information on the type of intervention (i.e. DA content must not be communicated in the control group). Subsequently, decisions will be made by patients and physicians during the consultation.

Randomisation and blinding

Randomisation will be conducted after collection of baseline-data. The randomisation sequence will be computer generated by the University of Hamburg. A pseudonym (code) for each patient will be created to save the patient´s anonymity. The code will be used to combine data sets (baseline data and data of the observation period) and to identify data if patients cancel informed consent. Code lists will be destroyed after completion of the study.


Primary outcome measure is the level of patient knowledge relating to the concept of risk, the notion of heart attack risk, and the benefits and harms of preventative treatment. Knowledge is captured by a standardised questionnaire.

Secondary outcome measures are 1) sustainability of knowledge; 2) achievement of individual treatment goals regarding the use of statins, levels of blood-pressure and glucose control, and smoking; 3) achievement of treatment goals prioritised by the individual patients; 4) medication uptake.

Outcome measures will be assessed directly after decision making and at 6 months of follow-up.

Sample size

Data on about 56 patients per group (112 participants) need to be included in data-analysis. Estimating a non-responder/drop-out rate of about 20%, 140 participants will be recruited for randomisation. In the year 2009, 280 patients of the study site (diabetes outpatient clinic, University of Jena) would have met the eligibility criteria of this study.

This power calculation was conducted by Dr. Thormas Lehmann Biostatistician (Jena, Gemany).

Qualitative research

The first three counselling sessions in the intervention group will be observed by research fellows of the University of Hamburg (named above). Observation aims at feasibility of the counselling at an outpatient clinic.

Phase 3: Evaluation of the ISDM programme in a cluster randomised controlled trial

Effectiveness of the ISDMP under implementation conditions will be evaluated in a cluster randomised controlled trial (cRCT) in practices of general practitioners (no diabetes clinics) who participate in the DMP type 2 diabetes and who practice in the Free State of Thuringia or Hamburg, Germany. The CONSORT-statement will be followed [36].

Provider training

The provider training will be given to the practitioners and their assistants after randomisation of the participating general practices to the study arms.

Recruitment and eligibility

In this cRCT, about 40 practices (clusters) will be invited for study participation. After the screening of patient records regarding eligibility, participant information will be given to eligible patients and informed consent will be documented for study participation. Then, practices will be randomised to the study arms. Subsequently, provider training will be given.


Primary outcome measure is the adherence to the individual choice regarding the use of statins (taking or not taking) for MI-prevention.

Secondary outcome measures are 1) the achievement of individual treatment goals regarding levels of blood-pressure and blood-glucose, and smoking; 2) achievement of treatment goals prioritised by the individual patient; 3) medication prescriptions; 4) therapeutic effort and 5) the level of patient knowledge relating to the concept of risk, the notion of heart attack risk, and the benefits and harms of preventative treatment. Knowledge and sustainability of knowledge are assessed by using a standardised questionnaire.


Self-reported adherence to statin intake will be assessed at six months follow-up using telephone interviews with patients. The interviews will be conducted by a study assistant of the study organising centre who is independent from the practices and who is blinded towards the allocation of clusters. Patients’ answers will be kept under lock. Additionally, health insurance data on statin choice (accounted prescriptions) will be obtained.

Qualitative research

Interviews will be conducted with practitioners and their assistants. The aim is the identification of problems associated with the implementation of the counselling in general practices.

Ethical approval has been granted for all three phases.



[1]       Gerstein HC, Miller ME, Byington RP, et al. (2008) Effects of intensive glucose lowering in type 2 diabetes. N Engl J Med 358: 2545-2559

[2]       U. K. Prospective Diabetes Study Group (1998) Tight blood pressure control and risk of macrovascular and microvascular complications in type 2 diabetes: UKPDS 38. BMJ 317: 703-713

[3]       Costa J, Borges M, David C, Vaz CA (2006) Efficacy of lipid lowering drug treatment for diabetic and non-diabetic patients: meta-analysis of randomised controlled trials. BMJ 332: 1115-1124

[4]       Lalonde L, O’Connor AM, Drake E, Duguay P, Lowensteyn I, Grover SA (2004) Development and preliminary testing of a patient decision aid to assist pharmaceutical care in the prevention of cardiovascular disease. Pharmacotherapy 24: 909-922

[5]       Sheridan SL, Shadle J, Simpson RJ, Jr., Pignone MP (2006) The impact of a decision aid about heart disease prevention on patients‘ discussions with their doctor and their plans for prevention: a pilot randomized trial. BMCHealth ServRes 6:121.: 121

[6]       Edwards A, Elwyn G (2009) Shared decision making in health care: achieving evidence based patient choice, 2e. Oxford University Press, Oxford

[7]       Kasper J, Kopke S, Muhlhauser I, Heesen C (2006) Evidence-based patient information about treatment of multiple sclerosis. A phase one study on comprehension and emotional responses. Patient Educ Couns 62: 56-63

[8]       Bunge M, Mühlhauser I, Steckelberg A (2010) What constitutes evidence-based patient information? Overview of discussed criteria. Patient Educ Couns 78: 316-328

[9]       Stacey D, Bennett CL, Barry MJ, et al. (2011) Decision aids for people facing health treatment or screening decisions. Cochrane Database Syst Rev: CD001431

[10]     International Patient Decision Aid Standards Collaboration (2005) What are Patient Decision Aids. Available from http://decisionaid.ohri.ca/IPDAS/what.html  accessed 4 October 2007

[11]     (2004) The Cochrane Inventory. Available from http://decisionaid.ohri.ca/cochinvent.php, accessed 10. November 2010

[12]     Lenz M, Kasper J, Mühlhauser I (2009) Development of a patient decision aid for prevention of myocardial infarction in type 2 diabetes – rationale, design and pilot testing. Psychosoc Med 6: Doc05

[13]     Healthwise Inc (2008) Healthwise Decision Point: I have diabetes. Should I get pregnant now? Available from http://www.healthwise.net/preferredcare/, accessed 26 June 2008

[14]     Mayo Clinic Rochester (2009) Diabetes Medication Choices. Diabetes treatment: Medications for type 2 diabetes. Available from http://www.mayoclinic.com/health/diabetes-treatment/DA00089, accessed 10. November 2010

[15]     Weymiller AJ, Montori VM, Jones LA, et al. (2007) Helping patients with type 2 diabetes mellitus make treatment decisions: statin choice randomized trial. Arch Intern Med 167: 1076-1082

[16]     Ng C (2009) Starting Insulin – Your Choice. University of Sheffield. University of Sheffield, Sheffield, UK

[17]     Lenz M, Steckelberg A, Mühlhauser I (2008) Patient education programmes and decision aids – evaluation of complex interventions. Av Diabetol 24: 443-452

[18]     Health Dialog (2007) Living with diabetes. Making lifestyle changes to last a lifetime. Foundation for Informed Medical Decision Making, Boston MA, USA

[19]     Corser W, Holmes-Rovner M, Lein C, Gossain V (2007) A shared decision-making primary care intervention for type 2 diabetes. Diabetes Educ 33: 700-708

[20]     Lenz M, Mühlhauser I (2009) Decision aids in Diabetes. In: Edwards A, Elwyn G (eds) Shared decision making in health care: achieving evidence based patient choice, 2e. Oxford University Press, Oxford, pp 285-295

[21]     Elwyn G, O’Connor A, Stacey D, et al. (2006) Developing a quality criteria framework for patient decision aids: online international Delphi consensus process. BMJ 333: 417

[22]     Kasper J, Lenz M (2005) Criteria for the development and evaluation of decision aids. ZArztlFortbildQualitatssich 99: 359-365

[23]     Lenz M, Kasper J (2007) MATRIX – development and feasibility of a guide for quality assessment of patient decision aids. GMS Psychosoc Med 4: Doc10

[24]     Craig P, Dieppe P, Macintyre S, Michie S, Nazareth I, Petticrew M (2008) Developing and evaluating complex interventions: new guidance. In. UK Medical Research Council

[25]     Lenz M, Mühlhauser I (2009) Zur Vorbeugung von Herzinfarkt bei Typ 2 Diabetes – Information and Entscheidungshilfe für Patienten (Prototyp). Available from http://www.chemie.uni-hamburg.de/igtw/Gesundheit/images/pdf/Decision_Aid_HerzinfarktpraeventionDM2.pdf

[26]     Lenz M, Mühlhauser I (2009) On the prevention of Heart Attack in Type 2 Diabetes – Information and Decision Aid for Patients (Prototype). Available from http://www.chemie.uni-hamburg.de/igtw/Gesundheit/images/pdf/20091019DAtranslation.pdf

[27]     Elwyn G, Edwards A, Wensing M, Hood K, Atwell C, Grol R (2003) Shared decision making: developing the OPTION scale for measuring patient involvement. Qual Saf Health Care 12: 93-99

[28]     Kasper J (2010) doktormit SDM – Ein Trainingsprogramm zur ärztlichen Risiko-Kommunikation & Patientenbeteiligung. In:  Workshop auf der 11 Jahrestagung DNEbM eV (im Rahmen des Forums Medizin 21), Salzburg 25. – 27. Februar 2010

[29]     Kasper J, Hoffmann F, Matthies S, Mosler M (2009) Manual MAPPIN’-SDM Multi-focal approach to the ‚sharing’ in SDM. Unveröffentlichte Projektarbeit. Universität Hamburg

[30]     Kasper J (2009) doktormit  SDM – A Training Program for Doctors on Risk Communication & Patient Involvement.

[31]     Kasper J (2009) Qualität Evidenz-basierter Arzt-Patient Kommunikation Akutschmerz- Interdisziplinäre Schmerztherapie – Der Patient im Fokus. In:  4 Akutschmerz – Kongress, Köln  4.-5 Dezember 2009

[32]     Kasper J, Legare F, Scheibler F, Geiger F (2010) Shared decision-making and communication theory: Grounding the tango. Z Evid Fortbild Qual Gesundhwes 104: 636-641

[33]     Kasper J, Heesen C, Köpke S, Geiger F (2011) Patients and Observers Perceptions of Involvement Differ. Validation Study on Inter-Relating Measures for Shared Decision Making. PLoS ONE 6(10): e26255

[34]     Kasper J, Köpke S, Heesen C, Geiger F Is SDM the same as SDM? Mismatch of different perspectives reveals limitations of existing measurement approaches. International Conference on Communication in Health Care: 2nd-5th,2010 Verona, Italy

[35]     Kasper J, Legare F, Scheibler F, Geiger F (2012) Turning signals into meaning – ‘Shared decision making’ meets communication theory. Health Expectations 15(1): 3-11

[36]     Schulz KF, Altman DG, Moher D CONSORT 2010 Statement: Updated guidelines for reporting parallel group randomised trials. J Clin Epidemiol 63: 834-840