Potential for Medical Error: Incorrectly Completed Request Forms for Thyroid Function Tests Limit Pathologists' Advice to Clinicians (Original ARTICLES‪)‬

Laboratory quality has been historically determined by the accuracy of the analytical phase. Following the development of high-quality analytical techniques, analytical error is no longer the main reason for error in the laboratory testing process. (1) Up to 68.2% of laboratory errors occur in the pre-analytical phase, (2) which refers to procedures performed neither in the clinical laboratory nor under the control of laboratory personnel, (3,4) e.g. completion of a laboratory request form, specimen identification, phlebotomy, sample handling and transportation to the laboratory. Post-analytical error refers to the ultimate check on the pre-and intra-analytical quality, including the reviewing pathologist providing interpretative comments, and the clinicians' interpretation and reaction to the results. (3,4) Interest is growing in the assessment of clinical laboratories' contribution to medical outcomes, including the evaluation of pre-and post-analytical errors. (5) Clinical authorisation of results provides a final quality check of the entire pre-analytical and laboratory process, and is an important addition to standard quality control procedures. (6) Clinical validation of biochemistry results includes the postanalytical addition of comments to a laboratory report; this should be done by a qualified person with knowledge of the potential pre-analytical and analytical variables that may influence the result. (7) Providing interpretative comments, especially to primary care physicians, is an important duty of chemical pathologists. (8) Owing to the paucity of clinical biochemistry training in undergraduate medical training programmes (9,10) and increased specialisation of medical staff, interpretative comments may be useful for requesting physicians. (6) The Royal College of Pathologists has guidelines for the provision of such comments. (11) The Clinical Pathology Accreditation (CPA) Standards state that interpretation of results is an important component of clinical laboratories' services. (12) External quality assessment of interpretative comments is in place in the UK, Australia and Italy. (8,13-17) Clinical diagnoses are often confirmed with the use of laboratory results and, therefore, laboratory errors may lead to increased costs and unnecessary deaths. (18)