Validation of a reduced instrument Diabetes-21 for assessing health related quality of life among people with diabetes

Abstract

Objective: To analyze the validity, reliability and interpretability of a reduced instrument for assessing health-related quality of life in diabetes. Methods: Crosssectional study with people with diabetes, consisting of the phases: adaptation of the Diabetes-39 instrument (5 dimensions and 39 items), pre-test, analysis of structural validity, reliability, concurrent validity and interpretability. Results: The factor structure of the final version of the reduced instrument was different from the original. There was a reduction from 39 to 21 items and a reduction from 5 to 4 dimensions. The factor loadings in the exploratory and confirmatory analyzes ranged between 0.41-0.90 and 0.51-0.89, respectively. Reliability was adequate (Cronbach's alpha=0.91; Kappa≥0.60 in all items; intraclass correlation coefficient=0.91). Conclusion: The Diabetes-21 instrument was considered valid, reliable and interpretable for assessing health-related quality of life among people with diabetes.