Laboratory diagnosis and geriatrics: more than just reference intervals for the elderly

As he/she approaches the end of life, the healthy elderly person comes to be seen rather as a "biological curiosity" than as a normal case. For laboratory testing it becomes increasingly difficult to determine appropriately stratified and statistically relevant reference groups. More appropriate would be individual monitoring, which, however, requires long-term stable quality in laboratory analyses. Despite "consolidation" in laboratory medicine, the pre-analytical phase, which is especially important in the elderly, remains underestimated. This problem is aggravated by insufficient harmonisation between laboratory tests, especially when point-of-care testing is included. Since in geriatrics, maintenance of life quality is more important than curative therapy, clinicians are forced to undergo therapeutic compromises applying symptomatic, supportive or palliative therapies. In this situation, information on "still remaining functional capacities" of organs is particularly helpful. Diagnostic problems resulting from underestimation of "multi-morbidity" and especially "multi-aetiology" can be complicated by "degradation of clinical information", especially in patients in cognitive and/or physical decline. The specific purpose of "geriatric" laboratory medicine seems to induce a change of paradigms: not only statistically established "evidence", but "individuality" in a single patient will need more profound insight. Not so much differentiation between "physiology" and "pathology", but the consideration of "clinical individuality" as relative risk in dimension of time is of importance.