7.5 Common Reference Intervals for Plasma Proteins in the Nordic Countries

It is a philosophic question whether it is possible to establish common reference intervals valid for different ethnic groups and geographical areas. From a practical viewpoint, however, reference intervals are in current use and seem to be the best tool for a general validation of the first results from persons consulting the health care system -when clinical strategies with clear interpretation of results are missing. The reference individuals should be selected and the measurements and calculations should be performed according to IFCC (1, 3) or equivalent (cf. section 7.1). An important point, however, is the decisions about dwiding and combining different reference intervals as investigated by Harris and Boyd (2). According to them the problem is mainly a statistical problem, but as discussed in chapters 7.1, 7.2 and 7.3, it is also a question of judgements based on biology.