Versão brasileira do questionário "quality of life - assessment of growth hormone deficiency in adults" (QoL-AGHDA) - tradução e validação em 4 estágios

Abstract

In face of the scarce evidence for definitive improvement in cardiovascular morbidity and mortality associated with growth hormone deficiency (GHD), the changes in well-being and quality of life have been one of the most compelling reason for the use of GH in patients with GHD. Many studies have shown improvements in quality of life of patients treated with GH in the last years, mainly using the Quality of Life - Assessment of Growth Hormone Deficiency in Adults (QoL-AGHDA) as the questionnaire follow-up instrument. In Brazil, only recently some health authorities are supplying selected adult GHD patients with GH, although still not on a protocol- based decision related to poor quality of life. Therefore, it would be quite useful to have a validated questionnaire which could be utilized as an instrument to possibly guide doctors and public organs with objective criteria concerning initiation and maintenance of GH therapy in adults. This would ultimately permit a rational use of this high cost prolonged treatment in GHD adults, as adopted in other countries. This study developed a validated adaptation of a Brazilian Portuguese version of the QoL-AGHDA for use in adult growth hormone deficient patients. The translation process adopted the dual panel methodology (bilingual and lay panels).The questionnaire was tested for applicability, comprehension, and relevance through field test interviews. In the final stage, data from 120 patients were analyzed for internal consistency (Cronbach´s alpha coefficients), test- retest reliability (correlating scores on the scales obtained from two different occasions), convergent validity (correlation between QoL-AGHDA and Nottingham Health Profile [NHP]) scores and known groups validity (comparison of scores to patient-reported general health). The adaptation of the QoL-AGHDA for a Brazilian population was successful with the adapted questionnaire shown to be reliable and valid. Cronbach´s alpha coefficients showed that all items contributed to the scale, and good reproducibility was confirmed by the test-retest assessment. Scale scores correlated well with NHP scores and the questionnaire distinguished well between patients based on their self-reported general health. These results overall show that this validated Brazilian version of the QoL-AGHDA is conceptually equivalent to the UK-English version. In conclusion, the Portuguese version of the QoL-AGHDA is a reliable and valid measure of QoL, suitable for inclusion in clinical studies and routine clinical practice. This instrument may ultimately help clinical decision concerning GH therapy based on QoL for GHD patients.