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Table 2 Agreement between eyes and staining techniques

From: The value of simple microbiological studies for on-site screening of acute neonatal conjunctivitis in Angola

  Concordance rate Weighted kappa coefficient
N % 95% CI of concordance rate Kappa 95% CI of kappa
   Lower limit Upper limit   Lower limit Upper limit
Methylene blue stain vs. Gram stain Epithelial cells LE 33 34.7 25.5 45.3 0.128 −0.0961 0.3516
RE 38 40.0 30.2 50.6 0.243 −0.0029 0.4882
Leukocytes LE 83 87.4 78.6 93.0 0.412 0.3074 0.5167
RE 89 93.7 86.2 97.4 0.381 0.3097 0.4525
RE vs. LE Epithelial cells Methylene blue stain 61 64.2 53.7 73.7 0.524 0.2990 0.7495
Gram stain 36 37.9 28.3 48.5 0.174 −0.0543 0.4024
Leukocytes Methylene blue stain 88 92.6 85 96.7 0.281 0.2104 0.3514
Gram stain 80 84.2 75 90.6 0.373 0.2673 0.4796
  1. RE right eye; LE left eye. Concordance values can vary between 0 (no concordance) and 1 (perfect concordance). Moderate concordance was considered to be 0.4 to 0.5, and good concordance was considered to be ≥ 0.6.