Measuring degradation of quality-of-life related to pollution in the SEQAP study

Development of an instrument to measure subjective concepts is a long process involving only marginally effective participation of statisticians. Most of the time, the main work is done by sociologist, psychologist, or health policy decision makers even if statistical methodology is always the main scientific foundation. In this chapter, using the opportunity of a real epidemiological and environmental study, we mainly present the methodology used of construction of a quality of life instrument specific to air pollution disturbance with a large emphasis on its statistical part. These methods are based on classical and modern psychometrical measurement models chosen in order to select questions measuring a few clear unidimensional latent traits (subjective concepts).