TABLE 3.

Bias and precision of Etest versus broth microdilution

Test groupNo. of EAs per site (%)aInterlaboratory reproducibility (%)b
Site 1Site 2Site 3
Aerobes1009692100
Nonpneumococcal streptococci100100100100
Anaerobes10010096100
S. pneumoniae10096100100
H. influenzae968888100
Total99.296.295.4100
  • a Etest readings ±1 log2 dilution of the reference method mode.

  • b Etest readings from all three tests sites ±1 log2 dilution of the Etest mode.