The best internal structure of the Diabetes Quality of Life Measure (DQOL) in Brazilian patients

Background Diabetes Mellitus (DM) is considered a chronic disease with numerous secondary complications that negatively affect the quality of life of patients. However, the specific, known and validated instruments for Brazilian Portuguese are too extensive, which often makes their use infeasible. Objective To validate the internal structure of the Brazilian version of the Diabetes Quality of Life (DQOL) measure. Methodology Patients with DM type 1 or 2, between the ages of 18 and 76, were evaluated between April 2022 and May 2022. The survey was conducted online using the Google Forms platform. The original DQOL contains 46 multiple-choice questions organized into four domains. For structural validity, confirmatory factor analysis (CFA) was performed using RStudio software (Boston, MA, USA) with the packages lavaan and semPlot. Results A total of 354 subjects were evaluated. The 3-domain, 24-item version of the DQOL was the most adequate, with acceptable values for all fit indices (chi-square/GL < 3, TLI and CFI > 0.90, and RMSEA and SRMR < 0.08). Conclusion The structure with three domains and 24 items is the most appropriate based on factor analysis. The Brazilian version of the DQOL with a structure of 3 domains and 24 items has adequate measurement properties that support its use in the clinical and scientific context in patients with DM.