The Leeds regional quality control scheme for clinical biochemistry: a progress report.

The results from a regional quality control scheme for clinical biochemistry are analysed. Comparison with results from an earlier period shows that the quality of several of the 15 routine analyses has improved. The methods by which the sera are produced and distributed, and the weekly results are analysed, are described. Each of the 25 laboratories receives an individual weekly computer printout within 24 hours of the deadline for the receipt of results. At the end of each six-month period a printout is produced ranking each laboratory for ;accuracy' and ;precision' for each test.