Disease management of co-morbid depression (DiMaCoDeA) in primary care patients with type 2 diabetes and/or chronic obstructive pulmonary disease (COPD) and/or Anxiety: a randomised controlled trial.

Background: Type 2 diabetes (DM2) and Chronic Obstructive Pulmonary Disease (COPD) are common chronic diseases that have a serious, negative impact on the quality of life. Patients with DM2 or COPD frequently suffer from co-morbid depression; approximately 10-15% has a co-morbid depressive disorder. Recent findings also show that depression in COPD or DM2 not only impacts on quality of life, but also hampers effective self-management behaviours in both conditions. For example, depressed diabetes patients are significantly more often in poor glycaemic control and have a higher risk for (further) diabetes complications. In patients with COPD, depression is associated with increased smoking behaviour and more exacerbations. Depression is a highly recurrent disease: within two years, 40% of the depressed patients have a recurrence of the depression. Depression can therefore be regarded as a chronic condition. Depression is also a costly disease: The Dutch Trimbos Institute recently estimated that the annual costs of depression are about 660.000.000 Euro in The Netherlands. However, in daily clinical practice, depression is often not recognised. Less than 50% of the patients with depression is detected, and depression therefore often remains untreated. In primary care, treatment usually consists of antidepressant medication. Treatment outcomes are often not monitored and the adherence to the antidepressant treatment is often low. A disease management approach for co-morbid depression could therefore help. Main elements of disease management are active screening for depression, stepwise treatment for depression, monitoring of outcomes and a multidisciplinary approach. However, the effectiveness of such a disease management approach for co-morbid depression in primary care patients with COPD or DM2 has not yet been tested in Europe. Aim and research questions: To conduct a randomised controlled trial in primary care patients with COPD or DM2, to test whether a disease management approach for co-morbid depression, compared to care as usual, has beneficial effects on: 1) mood and quality of life 2) health care costs 3) self-management 4) glycaemic control (DM2) en exacerbations (COPD). Subjects and research setting: The proposed randomised controlled trial will be conducted within the infrastructure of POZOB (Praktijk Ondersteuning Zuidoost Brabant), a large managed care organisation in the province of N-Brabant. In 2007, POZOB supported the practices of more than 160 primary care physicians and their 350.000 patients. When the present study will start in 2009, approximately 10.000 patients with DM2 and 5.000 COPD (Gold 1 of Gold 2) will be treated within POZOB. For the proposed study, 2300 patients with COPD and 2300 patients with DM2 will be invited to complete a depression questionnaire. Based on earlier results in POZOB research and care, we anticipate a response-rate of 70% (1610 questionnaires per patient group). At least 10% of these patients will suffer from co-morbid depressive disorder or sub-threshold depression (161 COPD, 161 type 2 diabetes); these patients will be invited to participate in the randomised controlled trial. Eligible patients will be randomised to care as usual (80 COPD, 80 DM2) or the intervention (80 COPD, 80 DM2), consisting of a disease management approach for co-morbid depression. We anticipate a drop out of 15%, allowing for sufficient power. In the unlikely case that the non-response and the drop out will be higher than expected, the infrastucture of POZOB allows for additional screening to include new patients. Outcome measures: For the depression screening, the Patient Health Questionnaire will be used (PHQ-9). The PHQ-9 is a widely used depression questionnaire that is based on the 9 diagnostic criteria for a depressive disorder (DSM-IV). Patients with a high score on the PHQ-9 will be invited to participate in the randomised controlled trial. The following outcome measures will be used in this trial at baseline, after the first part of the intervention (12 weeks) at six months and 12 months follow up. The EuroQol and the SF-36 (Quality of life and health status) and the Trimbos/iMTA questionnaire for cost associated with a psychiatric disorder will be used for cost effectiveness analyses. The glycaemic control will be measured with HbA1c in DM2 patients, and for COPD patients the number of exacerbations will be assessed. Physical activity is an important component of self-care in both type 2 diabetes and COPD. This construct will be measured using the Baecke Questionnaire. In addition, patients with diabetes will be asked to complete the Summary of Diabetes Self-care Activities measure, while both patients with COPD and diabetes are invited to complete the ASK-20 Adherence Barrier Survey. This instrument consists of 20 clinically actionable items representing multiple factors that affect medication adherence. The ASK-20 is suitable for use in diabetes and COPD.