[Automatic tracing of conversion scales from conventional units to the SI system of units].

American medical journals, as the Journal of the American Medical Association (JAMA), and the American Journal of Clinical Pathology (AJCP), the Journal of the American Society of Clinical Pathologists (ASCP), are shifting to selected SI (Système International d'Unités) units for reporting measurements. Further discussion by the AMA, the ASCP and other organizations is required before consensus in the US medical community can be reached as to the extent of and time frame for conversion to SI for reporting clinical laboratory measurements: however this decision will certainly greatly speed up the process of conversion in European countries too. Transition to SI units will require the use of different reference ranges, and there will be a potential for serious misinterpretation of laboratory data unless well-planned educational programs are instituted before the change. A simple program written in Microsoft Basic for automatically tracing on one's personal computer (PC) monitor a dual scale, in the conventional and in the SI system of units, is presented here. The program may be easily implemented and run on every PC operating under MS-DOS, equipped with a CGA or an AT&T6300 graphic card: through the operating system the scales may also be printed on a dot-matrix graphic printer. We believe that this, and other tools of this kind, will be useful in the thorough educational process of those reading the reports, and will be an important factor in the success of conversion to SI reporting.