Objective: To validate a diabetes-specific quality-of-life scale and to assess its psychometric properties in a large sample of patients with type 1 diabetes.
Research design and methods: To assess the quality of diabetes care in a population-based study, a representative sample of 684 patients with type 1 diabetes was examined. A total of 657 patients (42% female; mean age 36 years; mean diabetes duration 18 years) completed the diabetes-specific quality-of-life scale (DSQOLS), which comprised 64 items on individual treatment goals (10 items), satisfaction with treatment success (10 items), and diabetes-related distress (44 items). Statistical examinations covered factor analysis, internal consistency of subscales, and construct and discriminant validity.
Results: Factor analysis of the 44 items on diabetes-specific burdens revealed six reliable components (Cronbach's alpha): social relations (0.88), physical complaints (0.84), worries about future (0.84), leisure time flexibility (0.85), diet restrictions (0.71), and daily hassles (0.70). All six subscales were significantly correlated with a validated well-being scale (r = -0.35 to -0.53, P < 0.001) and treatment satisfaction (r = 0.28 to 0.43, P < 0.001). Physical complaints (r = 0.24) and worries about future (r = 0.17) showed the highest correlations with HbA1c (P < 0.001). A flexible insulin therapy, a liberalized diet, the absence of late complications, and a higher social status were significantly associated with more favorable scores in different domains.
Conclusions: The DSQOLS is a reliable and valid measure of diabetes-specific quality of life. The scale is able to distinguish between patients with different treatment and dietary regimens and to detect social inequities. Use of the DSQOLS for assessment of individual treatment goals as defined by the patients may be helpful to identify motivational deficits and to tailor individual treatment strategies.