1. Heyland DK, Guyatt G, Cook Deborah J (1998) Frequency and méthodologie rigor of quality-of-life assessments in the critical care literature. Crit Care Med 26:592–598
2. Clancy M, Eisenberg JM (1998) Outcomes research: Measuring the end results of health care. Science 282:245–246
3. McDowell I, Newll C (1996) The theoretical and technical foundations of health measurement. In: McDowell I, Newll C (eds) Measuring health: A guide to rating scales and questionnaires, 2nd edn. Oxford University Press, New York, pp 10–46
4. Juniper EF, Guyatt GH, Jaeschke R (1996) How to develop and validate a new health-related quality of life instrument. In: Spiker B (ed) Quality of life and pharmacoeconomics in clinical trials, 2nd edn. Lippincott-Raven Publishers, Philadelphia, pp 49–56
5. Feeny DH, Torrance GW, Furlong WJ (1996) Health utilities index. In: Spiker B (ed) Quality of life and pharmacoeconomics in clinical trials, 2nd edn. Lippincott-Raven Publishers, Philadelphia, pp 239–252