Desirable performance standards for imprecision and bias in alternate sites. The views of laboratory professionals.

Many strategies exist for the delineation of desirable performance standards for imprecision and inaccuracy (bias). All have disadvantages and advantages. Currently, the professional consensus is that the favored approach is based on biology: desirable imprecision is less than one half of the within-subject biological variation and desirable inaccuracy is less than one quarter of the group (within-subject plus between-subject) biological variation. Current laboratory performance allows these goals to be met for many quantities. In the past, analyses done at sites other than the laboratory achieved poorer results, but recent advances in technology appear to allow some biology-based goals, which in our view are the appropriate standards, to be met. Further advances in setting and widely promulgating goals, making good calibrants widely available, and developing quality control, assessment, and management are all required to ensure that the desirable performance standards are obtained in all locations in the future.