Assessing quality of life in diabetes: I. A practical guide to selecting the best instruments and using them wisely.

The rapid development of new medications and devices in diabetes research and clinical care has led to an increased need to assess their impact on health-related quality of life (HRQOL). Unfortunately, the lack of consensus definitions and guidelines has led to the use of HRQOL measures that are often imprecise and inappropriate. The goal of this report is to provide a practical structure to the definition and measurement of HRQOL in diabetes research and clinical care. Following a brief historical background to provide context, we define HRQOL and provide a three-step framework for scale selection: identify the specific, proximal intervention targets; decide how reaching these targets will affect HRQOL; and select appropriate measures based on sample diversity, the intervention and the targets using a 2×2 grid (generic vs. diabetes specific measures; global vs. component measures). Practical tips for scale selection include: gaining patient input to document important potential HRQOL effects, varying scale selection by patient characteristics, considering common HRQOL measurement problems, and considering the timing of HRQOL assessment. We emphasize the importance of a careful, planned evaluation of HRQOL in diabetes, rather than an "off the shelf" approach.