Diagnostic concordance between Amsel's criteria and the Nugent scoring method in the assessment of bacterial vaginosis

Bacterial vaginosis (BV) is diagnosed by the microbiological Nugent scoring method or clinical Amsel's criteria. Assessment of 404 vaginal samples (293 women) identified 110 (27.2%), 108 (26.7%) and 161 (39.9%) samples to be BV-positive using Nugent's method, standard Amsel's criteria and simplified Amsel's criteria respectively. The sensitivity, specificity, and kappa statistic (kappa) for standard and simplified Amsel's criteria were 71.8% (95% CI = 62.4-80.0), 90.1% (95% CI = 62.4-86.1), 0.62 (95% CI = 0.53-0.72) and 88.2% (95% CI = 80.6-93.6), 78.2% (95% CI = 73.1-82.8), 0.58 (95% CI = 0.49-0.67), respectively. A combination of vaginal pH and clue cells exhibited the highest concordance (kappa = 0.64, 95% CI = 0.54-0.74) with Nugent's method and may be used for simplified BV diagnosis.