Linguistic and Psychometric Validation of the Diabetes-Specific Quality-of-Life Scale in U.K. English for Adults With Type 1 Diabetes

OBJECTIVE To develop a linguistically and psychometrically validated U.K. English (U.K./Ireland) version of the Diabetes-Specific Quality-of-Life Scale (DSQOLS) for adults with type 1 diabetes. RESEARCH DESIGN AND METHODS We conducted independent forward and backward translation of the validated German DSQOLS. An iterative interview study with health professionals (n = 3) and adults with type 1 diabetes (n = 8) established linguistic validity. The DSQOLS was included in three Dose Adjustment for Normal Eating (DAFNE) studies (total N = 1,071). Exploratory factor analysis (EFA) was undertaken to examine questionnaire structure. Concurrent and discriminant validity, internal consistency, and reliability were assessed. RESULTS EFA indicated a six-factor structure for the DSQOLS (social aspects, fear of hypoglycemia, dietary restrictions, physical complaints, anxiety about the future, and daily hassles). High internal consistency reliability was found for these factors and the weighted treatment satisfaction scale (α = 0.85-0.94). All subscales were moderately, positively correlated with the Audit of Diabetes-Dependent Quality-of-Life (ADDQoL) measure, demonstrating evidence of concurrent validity. Lower DSQOLS subscale scores [indicating impaired quality of life (QoL)] were associated with the presence of diabetes-related complications. CONCLUSIONS The DSQOLS captures the impact of detailed aspects of modern type 1 diabetes management (e.g., carbohydrate counting and flexible insulin dose adjustment) that are now routine in many parts of the U.K. and Ireland. The U.K. English version of the DSQOLS offers a valuable tool for assessing the impact of treatment approaches on QoL in adults with type 1 diabetes.