BMC Public Health 2007, 7:74 http://www.biomedcentral.com/1471-2458/7/74 Background Diabetes mellitus is a major health problem. It was esti- mated that in 2000 approximately 177 million people worldwide had diabetes, and this number is expected to double by the year 2030 [1]. Cardiovascular disease is the leading cause of death among patients with diabetes. Both cardiovascular disease and diabetes are associated with similar risk factors, namely unhealthy diet, smoking and a sedentary lifestyle. These factors contribute to a severely elevated morbidity and mortality of patients with diabetes [2-5]. In the last few years it has been shown that interven- tions can lower these risk factors and improve cardiovas- cular and microvascular endpoints [6-10]. In previous studies it has been shown that different behav- ioural interventions are effective in changing lifestyle of patients with diabetes [11-14]. However, it is not entirely clear what kind of therapy is most effective [15]. We believe that a combined behavioural intervention, con- sisting of a motivational phase and problem solving tech- niques that is tailored to lifestyle determinants has to be used [11-14]. To our knowledge, this has not yet been studied. The aim of our study is to evaluate if adding a combined behavioural intervention to managed diabetes care, is effective in improving the cardiovascular risk profile of patients with type 2 diabetes. Diabetes Care System (DCS) In addition to the care of the GPs and their practice nurses, in West-Friesland, the Netherlands, an extensive diabetes management programme, is implemented [16]. In short, each patient visits annually the diabetes research center for a physical examination. In addition, the patient visits a diabetes nurse and a dietician for information and advice and is invited for follow-up visits when necessary. The results of this annual examination are sent to the patient's GP, who is responsible for the management of the patient and delegation of tasks to their practice nurse, according to the guidelines of the Dutch College of Gen- eral Practitioners. These guidelines recommend every patient with diabetes to visit a GP every 3 months [17,18]. At present, 3800 patients, representing 80% of all type 2 diabetes patients in the sub-region West-Friesland are enrolled in this Diabetes Care System (DCS). The mean HbA1c of these patients was 7.0% in 2005. However, according to current guidelines of the Dutch College of General Practitioners [18] more than 60% of the patients participating in the DCS still had a HbA1c ≥ 7.0% and 90% of the patients had a HbA1c ≥ 8.5%. In addition, 20% of the patients still smoked, 80% was overweight and 70% had little or no physical activity. These findings show that the DCS was successful in controlling hyperglycaemia, but failed with respect to the lifestyle factors. Our findings are similar to those of other diabetes management programs [19]. This implies that there is a need for innovative pro- grammes to improve the quality of care for diabetes patients, with a specific focus on lifestyle factors. Cognitive behavioural therapy (CBT) During the last few decades, several models have been developed to explain and predict health behaviour. A common used model is the Atittude, Social influence, and self-Efficacy model (ASE-model) [20-22]. It mainly incor- porates the attitudes and social influences determinants of the Theory of Reasoned Action and the self-efficacy con- cept of Bandura's Social Cognitive Theory [23]. This model has proven to be effective for developing behav- ioural interventions in different research areas and will be used in our study to evaluate if the determinants of behav- iour of the patient have changed after the CBT [24-26]. The ASE-model assumes that behaviour has three primary determinants: attitudes, social influences and self-efficacy. Together, they determine the intention of a person to per- form a specific behaviour. In this model, a person's atti- tude towards a specific behaviour is determined by its perceived affective (evaluative) and cognitive conse- quences. The social influences are determined by social norms, perceptions of the behaviour of others and per- ceived social support or pressure for execution of the behaviour. The self-efficacy expectations can be seen as a person's belief in his or hers ability to perform the desired behaviour in specific social, emotional and habitual situ- ations. These three determinants are not entirely inde- pendent of each other; they can all be seen as cognitions that the person has regarding the importance of execution of a specific behaviour. We developed a CBT that consists of two parts: Motiva- tional Interviewing and Problem Solving Treatment. Motivational Interviewing (MI) MI is a client-oriented, directive method for enhancing intrinsic motivation to change by exploring and resolving ambivalence [27]. The four guiding principles of MI are: express empathy, develop discrepancies, roll with resist- ance and support self-efficacy. Expressing empathy involves providing clients with an atmosphere of respect and acceptance of their position. The technique used is reflective listening and this is gener- ally considered the foundation of MI and is recom- mended throughout the whole counselling process. The second principle of MI involves creating a 'gap' between the client's current behaviour and their broader goals, thus cultivating motivation for lifestyle change. Page 2 of 10 (page number not for citation purposes)