Expert opinion on life expectancy must make reasonable factual assumptions, which entails finding a proper group to which the individual being assessed will be compared, as well as use of appropriate and reliable technical methods. Reasonable judgment should be exercised in the selection of the studies employed. A schedule of mortality rates must be built on a fair assessment of the person's medical condition and of relevant peer-reviewed findings. A clear and detailed report should be produced, containing the basis for the opinion, the description of the methods employed, and the life-expectancy calculations specific to the individual.