Reference values for residual volume, functional residual capacity and total lung capacity. ATS Workshop on Lung Volume Measurements. Official Statement of The European Respiratory Society

Reference values play an important role in establish-ing whether, in an individual, measured volumes fall within a range to be expected for a healthy person of the same sex, similar stature, age, and other characteristics. Hence, reference values should be chosen that are appro-priate to the person being investigated. Ideally, the refe-rence values should be consistent; in the context of this paper, it implies that predictions for the various lung vol-umes have been derived from the same reference popu-lation, with the same techniques. Comparing measured with reference values is fraught with difficulties, as it may lead to disease going undetected. This is because the scatter in predicted values is sufficiently large to allow a sick person to lose, e.g. much of his total lung capacity (TLC), whilst still remaining in the range observed