http://www.cdc.gov/hrqol/pdfs/mhd.pdf

This technical report, Measuring Healthy Days, describes the origins, validity, and use of a set of survey measures developed by the Centers for Disease Control and Prevention (CDC) and its partners for tracking population health status and Health-Related Quality of Life (HRQOL) in states and communities. The report is intended for public health professionals involved or interested in HRQOL surveillance or measurement. The report identifies the policy and conceptual origins of a brief set of healthy days HRQOL measures developed for use as public health outcome measures and summarizes the results of studies to test the measures' accuracy and consistency.