In principle each MAU instrument purports to measure the ‘utility’ of a health state; that is, each purports to measure the strength of a person’s preference for that health state. Consequently, the numbers produced by instruments should be the same. In practice they differ very significantly. Drawing upon results from 7720 respondents the ‘Multi Instrument Comparison’ (MIC) project has demonstrated that different instruments are sensitive to different dimensions or facets of a health state. The EQ-5D primarily measures physical function and pain. The AQoL-8D largely measures psycho-social facets to which the EQ-5D is relatively insensitive. The MIC research papers provide pairwise comparisons of all MAU instruments and quantifies their responsiveness to different dimensions of the QoL (see Richardson, Iezzi, Khan, Maxwell 2012 A cross-national comparison of 12 quality of life instruments, MIC Paper 2: Australia Research Paper 78, CHE Monash University. Results for UK, USA, Canada and Norway are in subsequent reports).