Table 2

Analysis of PD-L1 tumour-cell staining concordance between PD-L1 IHC 22C3 and 28-8 assays across PD-L1 expression levels

PD-L1 expressionAll biopsies (n=1930)Biopsies with a confirmed lung cancer diagnosis (n=412)
≥1%≥5%≥10%≥25%≥50%≥1%≥5%≥10%≥25%≥50%
PPA
(95% CI)
97%
(96 to 98)
97%
(95 to 98)
98%
(96 to 98)
98%
(97 to 99)
99%
(97 to 99)
97%
(95 to 99)
97%
(93 to 98)
98%
(95 to 99)
98%
(94 to 99)
99%
(96 to 100)
NPA
(95% CI)
97%
(96 to 98)
97%
(96 to 98)
98%
(96 to 98)
97%
(96 to 98)
96%
(95 to 97)
96%
(92 to 98)
94%
(89 to 96)
96%
(93 to 98)
96%
(93 to 98)
97%
(94 to 99)
OPA
(95% CI)
97%
(96 to 98)
97%
(96 to 97)
98%
(97 to 98)
98%
(97 to 98)
97%
(96 to 97)
97%
(95 to 98)
95%
(93 to 97)
97%
(95 to 98)
97%
(94 to 98)
98%
(96 to 99)
Cohen’s kappa
(95% CI)
0.94
(0.93 to 0.96)
0.93
(0.92 to 0.95)
0.95
(0.94 to 0.96)
0.95
(0.93 to 0.96)
0.92
(0.90 to 0.94)
0.94
(0.90 to 0.97)
0.90
(0.86 to 0.94)
0.94
(0.91 to 0.97)
0.93
(0.89 to 0.97)
0.95
(0.92 to 0.98)
  • PPA and NPA calculations use 28-8 as the reference standard.

  • IHC, immunohistochemistry; NPA, negative per cent agreement; OPA, overall per cent agreement; PD-L1, programmed death ligand 1; PPA, positive per cent agreement.