In this cross-sectional study, we assessed the possible association of vitamin D deficiency with self-reported treatment satisfaction and health-related quality of life in patients with type 2 diabetes. We performed a sub-analysis of a previous study and included a total of 292 type 2 diabetic patients. We evaluated treatment satisfaction and health-related quality of life through specific tools: the Diabetes Treatment Satisfaction Questionnaire and the Audit of Diabetes-Dependent Quality of Life. Vitamin D deficiency was defined as 25 (OH) D serum levels < 15 ng/mL. Multivariable linear regression models were used to estimate the relationship of vitamin D deficiency with both outcomes once adjusted for self-reported patient characteristics. Vitamin D deficiency was significantly associated with the final score of the Diabetes Treatment Satisfaction Questionnaire and the single “diabetes-specific quality of life” dimension of the Audit of Diabetes-Dependent Quality of Life (p = 0.0198 and p = 0.0070, respectively). However, lower concentrations of 25-OH vitamin D were not associated with the overall quality of life score or the perceived frequency of hyperglycaemia and hypoglycaemia. Our study shows the association between vitamin D deficiency and both the self-reported diabetes treatment satisfaction and the diabetes-specific quality of life in patients with type 2 diabetes.

Diabetic foot ulcer (DFU) is a chronic complication that negatively affects the quality of life (QoL) of diabetic patients. In Spain, there is no specifically designed and validated instrument to assess the QoL of patients with DFU. Our aim was to adapt the Diabetic Foot Ulcer Scale-Short Form (DFS-SF) questionnaire to a Spanish population and validate it. A prospective, observational design was used. The DFS-SF was administered by personal interview. The validated SF-36 and EQ-5D generic instruments were used as reference tools. The reliability, validity, and sensitivity to changes were assessed using standard statistical methods. A sample of 141 patients with DFU was recruited. The content validity was 3.46 on average (maximum score of 4). The internal consistency of the DFS-SF subscales showed a standardized Cronbach’s α range between 0.720 and 0.948. The DFS-SF domains showed excellent reproducibility measures (intraclass correlation coefficient from 0.77–0.92). The criterion validity was good with significant correlations between each DFS-SF subscale and its corresponding SF-36 and EQ-5D subscales (p < 0.001). However, the questionnaire structure was not validated (comparative fit index = 0.844, root mean square error of approximation = 0.095, and standardized root mean square residual = 0.093). The instrument showed high sensitivity to ulcer changes over time (p < 0.001). The adapted and validated Spanish version of the DFS-SF questionnaire has good psychometric properties and shows good sensitivity to ulcer changes, although the construct validity was not optimal. The adapted questionnaire will be a useful tool specifically to assess the QoL in subjects with diabetic foot ulcers in the clinical and research settings in Spain.

Diabetic foot ulcers (DFU) negatively affect the quality of life (QoL) of people with diabetes. The Cardiff Wound Impact Schedule (CWIS) questionnaire has been designed to measure the QoL of people with chronic foot wounds. However, no studies have been specifically designed to validate this instrument in a Spanish population. In this prospective study, a total of 141 subjects with DFU were recruited. DFU was determined by performing physical examinations. Medical records were exhaustively reviewed to collect clinical variables. The CWIS was transculturally adapted by a group of experts and a group of patients with DFU. The SF-36 and EQ-5D generic instruments were used as reference tools. The questionnaires were administered at 7 days and 4, 12, and 26 weeks after the baseline assessment by personal interview with each of the study subjects. The psychometric properties of the instrument were assessed using statistical methods. The content validity had an average of 3.63 (90.7% of the maximum score of 4). The internal consistency of the CWIS subscales had a standardized Cronbach’s alpha range from 0.715 to 0.797. The reproducibility was moderate with an intraclass correlation coefficient (ICC) range from 0.606 to 0.868. Significant correlations between CWIS domains and SF-36 and EQ-5D subscales were observed, demonstrating a good criterion validity of the CWIS questionnaire (p < 0.001). However, the construct validity of the CWIS was not validated with a comparative fit index (CFI) of 0.69, a root mean square error of approximation (RMSEA) of 0.09, and a standardized root mean square residual (SRMR) of 0.10. The sensitivity to changes over time was optimal in the three domains (i.e., social life, well-being, and physical symptoms) (p < 0.001). In conclusion, the Spanish version of the CWIS shows acceptable psychometric properties to assess the QoL of subjects with DFU, except for its construct validity.