Validation of a reduced instrument Diabetes-21 for assessing health-related quality of life among people with diabetes. / Validação do instrumento reduzido Diabetes-21 para avaliação da qualidade de vida relacionada à saúde em pessoas com diabetes.

ABSTRACT

OBJECTIVE: To analyze the validity, reliability and interpretability of a short form instrument for assessing health-related quality of life among people with diabetes mellitus. METHODS: This was a validation study, comprised of the adaptation phases of the Diabetes-39 instrument (consisting of 5 domains and 39 items), pre-test, structural validity analyses (exploratory and confirmatory), reliability, concurrent validity and interpretability. RESULTS: The factorial structure of the short final version differed from the original instrument. The items were reduced from 39 to 21 and domains from 5 to 4. The factor loading, in exploratory and confirmatory analyses, ranged between 0.41 and 0.90 and between 0.51 and 0.89, respectively. Reliability was adequate (Cronbach's alpha=0.91; Kappa≥0.60 in all items; intraclass correlation coefficient =0.91). CONCLUSION: Diabetes-21, a short form instrument, was considered valid, reliable and interpretable for assessing health-related quality of life among people with diabetes mellitus.