(SF-6D) can be derived from the SF-36, or alternatively the SF-12 generic health surveys. The SF-6D (SF-36) uses 11 of the 36 questions to create six domains, each rated with between four and six levels of severity which in combination describe a possible 18,000 states. Health state valuations range from 1 to 0.30 (on a scale where 0 equals death and 1 equals perfect health). See: Brazier, J., Roberts, J., and Deverill, M. The estimation of a preference-based measure of health from the SF-36. Journal of Health Economics 2002;21:271-292; Brazier JE, Roberts J. Estimating a preference-based index from the SF-12. Medical care 2004;42:851-859.