Evaluation of the quality of life in Brazilian diabetic patients: comparison between specific and generic free instruments

The aim of this study was to compare two free tools, the specific Diabetes Quality of Life Measure (DQOL) and the generic Nottingham Health Profile (NHP), which measure the health-related quality of life (HRQL), in Brazilian patients with diabetes mellitus (DM). The DQOL and NHP were administered to 150 adult patients with type 1 diabetes mellitus (DM1) and 146 adult patients with type 2 (DM2). The scores were compared with age, time since diagnosis of DM, glycated haemoglobin (A1c), insulin use and the presence of secondary complications; for patients with DM2, the Diabetes Complications Index (DCI) was also administered. Factor analysis demonstrated similarity in the principal distribution of components in the two instruments, and there were low to moderate correlations between their domains. The NHP was directly correlated with patient’s age. DQOL was directly correlated with time since diagnosis of DM and A1c levels. The NHP predicted secondary complications of DM1. Both instruments had a direct correlation with the DCI, but the results were more significant for the NHP. The impact of insulin use was better identified by the DQOL. The NHP does not replace the DQOL for quality of life assessment in diabetic patients. However, its usefulness is not limited to the comparison of HRQL perception between diabetic and nondiabetic patients because the NHP is more sensitive than the DQOL in evaluating the impact of secondary complications of DM on HRQL.