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

Journal of Ophthalmic Inflammation and Infection

Table 2 Agreement between eyes and staining techniques

			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
	Epithelial cells	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
	Leukocytes	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
	Epithelial cells	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
	Leukocytes	Gram stain	80	84.2	75	90.6	0.373	0.2673	0.4796

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.