Table 3
Concordance correlation coefficients (
r
c
) for all four antigens
PT antigen
a
r
c
between pairs of laboratories for the PT antigen
PT1
0.90–0.98
PT2
0.93–0.99
PT3
0.92–0.98
PT4
0.93–0.99
↵
a
PT, pertussis toxin.