Health-related quality of life measurement in type 2 diabetes.

Type 2 diabetes has significant adverse effects on health-related quality of life (HRQoL). A vast array of questionnaires has been used to measure HRQoL in diabetes patients, contributing to the difficulty of selecting instruments for future research. To systematically evaluate these measures, a literature search was undertaken to identify relevant publications. This paper summarizes the generic, diabetes-specific, and psychological measures utilized to evaluate persons with type 2 diabetes, and highlights related findings. Generic instruments demonstrate significant reductions in health status compared with other chronic disease populations and healthy controls. Multiple diabetes-specific measures are available to assess domains affected by the disease, including symptoms, worries, self-care, locus of control, functional ability, social support, and sexual functioning. Psychological measures show that type 2 diabetes is frequently associated with adverse psychological effects, particularly depression. Since much of this research has been cross-sectional in nature, little is known about responsiveness of many of the HRQoL measures to clinical change and treatment effects. It is clear that HRQoL results are influenced by multiple patient and disease factors, particularly age, gender, and the presence and severity of disease complications and comorbid conditions. These factors should be considered in the design and analysis of HRQoL evaluations in type 2 diabetes patients. Selection of instruments for future research will therefore require careful evaluation of study design and objectives, population characteristics, the presence of disease-related factors, and outcomes of interest.