Evaluation of a Diabetes-specific Cognitive Behavioural Treatment for Subthreshold Depression

The Center for Epidemiologic Studies Depression Scale (CES-D) was used to assess depressive symptoms. The CES-D assesses the frequency of 20 typical symptoms of depression during the previous week on a 4-point Likert scale. Summing of the item scores estimates the total score with a range between 0 and 60 and higher scores indicating more severe depressive mood. Based on the measurement of depressive symptoms at baseline and 12-month follow up, the difference of the test scores between baseline and 12 month follow up was calculated.

The EuroQol Five Dimension Questionnaire (EQ-5D) was used to assess health-related quality of life (HRQOL). The EQ-5D assesses five dimensions of HRQOL using a 3-point scale. The item scores are weighted based on population data and used to calculate a standardised total score from 0 to 1 with higher scores indicating better HRQOL. Based on the measurement of HRQOL at baseline and 12-month follow up, the difference of the test scores between baseline and 12 month follow up was calculated.

The Problem areas in Diabetes Scale (PAID) was used to assess diabetes-specific distress. The PAID assesses diabetes-specific distress using 20 items and a five-point Likert scale (0 - 4). Item scores are summed and transformed to a range from 0 - 100 with higher scores indicating higher distress. Based on the measurement of diabetes-specific distress at baseline and 12-month follow up, the difference of the test scores between baseline and 12 month follow up was calculated.

The Summary of Diabetes Self-Care Activities Measure (SDSCA) was used to assess diabetes self-care. The SDSCA assesses the number of days of the previous week (0 - 7) on which several specific self-care activities (appropriate diet, physical activity, self-monitoring of blood glucose, foot care) were performed. The item scores are summed and averaged to a total score from 0 to 7 with higher scores indicating better overall self-care. Based on the measurement of diabetes self-care at baseline and 12-month follow up, the difference of the test scores between baseline and 12 month follow up was calculated.

The Acceptance and Action Diabetes Questionnaire (AADQ) was used to assessment of diabetes acceptance. Using 11 items on diabetes-related experiential avoidance behaviours and a 5-point Likert response scale (1 - 5), the AADQ estimates the overall level of diabetes acceptance. Item scores are summed to a total score between 11 and 55 with higehr scores indicating better acceptance. Based on the measurement of diabetes acceptance at baseline and 12-month follow up, the difference of the test scores between baseline and 12 month follow up was calculated.

The HbA1c was used as measure of glycemic control. All blood samples were analysed in a central laboratory using the Bio-Rad II Turbo analyser; the measurement units were %-points. Based on the measurement at baseline and 12-month follow up, the difference of the HbA1c values between baseline and 12 month follow up was calculated.

The inflammatory marker Interleukin 6 (IL-6) was assessed as measure of distress-related immune activity. The differences of the serum-concentrations between baseline and 12 month follow up were calculated.

The inflammatory marker Interleukin 1 receptor antagonist (IL-1Ra) was assessed as measure of distress-related immune activity. The differences of the serum-concentrations between baseline and 12 month follow up were calculated.

The inflammatory marker high sensitivity C-reactive protein (hs-CRP) was assessed as measure of distress-related immune activity. The differences of the serum-concentrations between baseline and 12 month follow up were calculated.

Several aspects of interest regarding diabetes-related health-care costs were assessed in order to evaluate potential reductions of health-care costs following the treatment. Measurement was performed using retrospective interview refering to the previous 6 months: The assessed aspects were 1.) the number of out-patient medical appointments as a measure of costs related to health-care utilisation, 2.) the number of days on sick leave as a measure of costs related to non-productive time and 3.) the number of daily taken prescription medications as a measure of costs related to medication intake. For each aspect, the difference of the numbers between baseline and 12 month follow up was calculated.

Several aspects of interest regarding diabetes-related health-care costs were assessed in order to evaluate potential reductions of health-care costs following the treatment. Measurement was performed using retrospective interview refering to the previous 6 months: The assessed aspects were 1.) the number of out-patient medical appointments as a measure of costs related to health-care utilisation, 2.) the number of days on sick leave as a measure of costs related to non-productive time and 3.) the number of daily taken prescription medications as a measure of costs related to medication intake. For each aspect, the difference of the numbers between baseline and 12 month follow up was calculated.

Several aspects of interest regarding diabetes-related health-care costs were assessed in order to evaluate potential reductions of health-care costs following the treatment. Measurement was performed using retrospective interview refering to the previous 6 months: The assessed aspects were 1.) the number of out-patient medical appointments as a measure of costs related to health-care utilisation, 2.) the number of days on sick leave as a measure of costs related to non-productive time and 3.) the number of daily taken prescription medications as a measure of costs related to medication intake. For each aspect, the difference of the numbers between baseline and 12 month follow up was calculated.