SF6D

SF-6D is a generic, preference-based measure of health-related quality of life that converts responses from the SF-36 (and in some applications the SF-12) into a single utility score used to estimate quality-adjusted life years (QALYs) in economic evaluations. It is designed to facilitate economic analyses in health care by providing a concise, standardized health-state value derived from widely used survey data.

Developed in the early 2000s by Brazier, Roberts, Deverill and colleagues, SF-6D offers a concise health-state classification drawn from 11 items of the SF-36. The instrument yields a summary measure of health status as a utility value suitable for incorporation into cost-utility analyses.

The SF-6D comprises six dimensions: physical functioning, role limitations, social functioning, pain, mental health, and vitality. Each dimension has multiple response levels, producing thousands of possible health states. A population-based scoring algorithm assigns a utility value to each state on a scale typically ranging from 0 (dead) to 1 (full health), with some valuation sets allowing values below 0 for states judged worse than death.

Applications and interpretation: SF-6D is widely used in economic evaluations, particularly when SF-36 data are available. It provides a practical alternative to other generic measures such as the EQ-5D and can be more compatible with SF-36-derived data. Its sensitivity to change varies by condition and population.

Limitations and considerations: The six-domain structure offers a narrower descriptive system than the full SF-36, which can affect sensitivity to certain health changes. Utility weights differ by country and study, complicating cross-country comparisons. There may be ceiling effects in healthier populations, and translations/validation studies exist for many languages.