Validez y reproducibilidad del sistema de puntuación de nugent para el diagnóstico de vaginosis bacteriana en mujeres embarazadas

Abstract

Background: The bacterial vaginosis is found in 15% to 20% of the pregnant women and the study of the vaginal discharge using the Amsel criteria is the usual method to diagnose it. However, there are other diagnostic methods like the Nugent Score System which has shown to be accurate and less expensive. Objective: To evaluate the accuracy and reliability of the Nugent Score System for diagnosing bacterial vaginosis in pregnant women. Methods: This is a study for evaluating medical tests. We studied 100 women who had a low risk pregnancy. Two samples of the vaginal discharge were taken in each woman and three masked evaluators examined each sample. The accuracy of the Nugent Score System was evaluated compare it with the Amsel criteria as a gold standard. To calculate the sensibility, specificity, positive predictive value, and negative predictive value of the Nugent Score System, we got the best cut point from the Nugent Score System using the receiver operator curve (ROC). The reliability was measured using the Kappa coefficient. Results: The average age was 25.6 years and the average gestational age was 23 weeks. A 19% of the women had had a vaginal infection previously. The current prevalence of bacterial vaginosis was 16% (95%Cl: 9.43%; 24.67%). The ROC analysis showed an area under the curve of 0.98 (95%Cl: 0.95; 1.00). The sensitivity was 1.00 (95%Cl: 0.77; 1.00), the specificity 0.96 (95%Cl: 0.90; 0.99), the positive predictive value 0.82 (95%Cl: 0.57; 0.96), and the negative predictive value 1.00 (95%Cl 0.95; 1.00). Conclusion: The Nugent Score System for diagnosing bacterial vaginosis in pregnant women is a valid and reproducible test for being implemented routinely during the prenatal care.