Laboratory intercomparison of commerical digoxin kits.

Results of recovery, precision, and effect of a protein deficient matrix on commercial digoxin assay kits is reviewed for pools distributed in 1978 by the Basic Ligand Assay Survey Program of College of American Pathologists. Variability among kits is present in terms of all three areas studied. Nevertheless, commonly used methods by participants have recovery rates approaching 100%; coefficients of variation are less than 10% at therapeutic serum levels.