Reproducibility of a scoring system for gram stain diagnosis of bacterial vaginosis

A total of 225 pairs of duplicate Gram-stained slides from three hospitals in Jakarta were evaluated independently by a local (University of Indonesia, Jakarta) and a referral (University of Washington, Seattle) laboratory by the new scoring criteria proposed by Nugent et al. The correlation coefficients of the duplicate Gram stain scores ranged from 0.65 to 0.83. The kappa statistics for the bacterial vaginosis category (no, score of 0 to 6; yes, score of 7 to 10) ranged from 0.62 to 0.77. These findings confirm the good to excellent interobserver reliability of the new scoring system and the importance of slide preparation.