Standards for the medical laboratory--harmonization and subsidiarity.

An International Standard, ISO 15189, specifically for 'Quality management in the medical laboratory' for use by accrediting 'bodies that recognize the competence of medical laboratories,' is expected to be published shortly. The origins, content and limitations of the new standard are discussed and the diversity of current arrangements for accreditation is reviewed. A new International Standard is an important step towards harmonization of laboratory practice but an accreditation system is more than its standards and a harmonized approach to the treatment of noncompliances found at inspection is important. Experience gained in writing national standards can improve the approach to the drafting and improvement of International Standards. Recognition of the principle of subsidiarity aids rather than hinders progress to harmonization and empowers the 'fourth element' (the laboratories to be accredited) to be a part of the accreditation process.