BMC Public Health 2007, 7:74 http://www.biomedcentral.com/1471-2458/7/74 Intervention group Patients who are assigned to the intervention group receive CBT in addition to the same managed care. The CBT is performed by diabetes nurses and dieticians, who received a training of two days in the performing of CBT prior to the onset of the study. Additionally, two instruc- tion days on the implementation of the intervention were arranged. A treatment manual is used during the study to guide the treatment. All CBT sessions are tape-recorded to assess treatment fidelity of the diabetes nurse or dietician to the protocol. In addition, these tape-recordings are used in supervision sessions to provide ongoing feedback. Each diabetes nurse and dietician haves supervision once every four weeks with a psychologist (PvO) who is special- ised in CBT. This psychologist is also available by email or telephone between the supervision sessions. A pilot study was performed before the start of the study to provide three practice sessions for each diabetic nurse and dietician and to assess logistic pathways of the study. There were 10 caregivers involved in the study, which means that 30 patients were included in the pilot study. A supervision meeting was scheduled after the pilot study to discuss logistic pathways and skills to perform the CBT of every caregiver. The CBT starts with a visit to the diabetes nurse. Results of the baseline measurements can be used to motivate the patient to change. With the help of MI techniques, a prob- lem list is created by the patient focused on lifestyle (smoking behaviour, diet and physical activity). When the most important problem is related to smoking or physical activity, the patient visits the diabetes nurse during the next sessions. When the most important problem is related to diet, the patient is rescheduled to visit the dieti- cian during follow-up sessions. From that moment, the patient remains with the same diabetes nurse or dietician during the entire study. After the MI phase, is it time to strengthen commitment to a lifestyle change plan. At this point, the patient is willing and able to change. Signs of this readiness for change are: decreased resistance, decreased discussion about the prob- lem, reaching some kind of resolution, increasing change talks, questions about the change, and envisioning how life might be after a change. At this time, the diabetes nurse or dietician makes, together with the patient, an implementation plan where, when and how the behav- iour changes will be performed. The formulation of this plan makes it easier for patients to carry out intended actions. This will be done by PST [28-31]. The CBT consists of three to six visits of 30 minutes to the diabetes nurses or dieticians at the DCS. There is a focus on one problem area in each session. During all sessions, both the MI and the PST skills are used to motivate the patients, set new goals and review the patients' progress. The last CBT session is brought to an end by reviewing and emphasising the entire CBT process, with emphasis on achieved successes of the patient and implementation of CBT in the future, independently of the diabetes nurse or dietician. The GPs provide ongoing feedback during the intervention. Co-interventions and compliance Co-interventions are avoided during the intervention by means of the fact that the control group was scheduled to a diabetes nurse that did not receive the training on CBT. In addition, all caregivers in the Diabetes Care System have access to the same central database which includes clinical characteristics of the patients and details on given advice and information. This centralisation avoids co- interventions. However, any co-intervention is reported. Compliance to the CBT is assessed by registration of the number of sessions that patients attend. Compliance to the intervention is considered adequate when at least three sessions are attended. For the patients in the control group, the number of follow-up visits to the diabetes nurse or dietician is also registered. The number of visits to the GPs or hospital is registered for both the intervention and the control group. Outcome assessment Outcome measurements are assessed at baseline, and again after 6 and 12 months by means of self-reported questionnaires and physical examinations at the DCS. Physical examinations are performed by medical assist- ants of the DCS. These included weight, height, waist cir- cumference, blood pressure, fasting blood glucose, HbA1c, triglycerides (at baseline and 12 months only), total cholesterol (at baseline and 12 months only) and HDL-cholesterol (at baseline and 12 months only). Demographic variables on age, gender, diabetes duration, marital status, ethnicity, level of education and eventual occupation are assessed at baseline by using a self-admin- istered questionnaire, which also includes all secondary outcomes. The medical assistants ask the patients infor- mation on medication (the patient brings the packages of medication to the visit), hospital admission days and number of general practitioner visits. Patients are informed of their measurements by the diabetes nurse and dietician. Measurements are also send to their GPs. Primary outcome measures The primary outcome measure is the difference between intervention and control group in change in cardiovascu- lar risk score after 12 months. The cardiovascular risk score is based on the Oxford Risk Engine (algorithm that includes: age at diagnosis, duration of diabetes, sex, eth- Page 6 of 10 (page number not for citation purposes)