Internal structure and psychometric properties of Diabetes Distress Scale for Type 1 Diabetes.

Diabetes-related distress (DD) refers to the worries and concerns about the nature and complications of Type 1 diabetes (T1D) and the frustration with the burdens of its management. Research suggests that sources of DD among people with T1D differ from those among Type 2. Many adults with T1D experience difficulties that are often unrecognised, unaddressed and mismanaged. The Diabetes Distress Scale for Type 1 diabetes (T1-DDS), is a newly developed instrument that is used to identify the specific sources of DD, exclusively for adults with T1D. The aim of the study was to examine the factorial structure of T1-DDS in Greek population and to evaluate its psychometric properties for use in research and clinical practice. A sample of 102 adults with type 1 diabetes, aged 38.85 (±10.08) years, females 63%, BMI 21.45 (±5.84) kg/m2, diabetes duration 21.35 (±13.73) years, HbA1c 7.5% (±1.2;58 mmol/mol) completed the translated T1-DDS. Exploratory factor analysis (EFA) and confirmatory (CFA) factor analysis were used to investigate the factor structure of the scale. Reliability was explored by internal consistency. Convergent validity was assessed through correlations with measures of psychological distress and diabetes status variables. Differential validity was assessed on the basis of known-group comparisons, with expected differences in distress for gender and age. Confirmatory factor analysis provided a low fit for the 7-factor model. Exploratory factor analysis supported a conceptually justifiable 5-factor model in the Greek sample. Internal consistencies of all five factors ranged from α=0.76 to 0.89. As expected, all factors were correlated with psychological distress [(r=0.510, p<0.01) for the total scale]. Management distress was positively correlated with HbA1c (r=0.397, p<0.01) and BMI (r=0.296, p<0.01), and Family/Friends distress was negatively correlated with duration of diabetes (r=-0.298, p<0.01). Further analyses showed that men exhibited higher score in relations to the social context of diabetes management (t=2.164, p<0.05 for Negative Social Perceptions), (t=2.572, p<0.05 for Family/Friends distress), and younger participants reported significantly higher distress in relation to reactions from friends and family (t=2.106, p<0.05). The Greek version of T1-DDS is a valid and reliable measure of diabetes-related distress that can be used in clinical practice to address personal needs and direct targeted interventions.