Chromoendoscopy with red phenol in the diagnosis of Helicobacter pylori infection.

An analytic study to validate a diagnostic test was carried out at the Institute of Gastroenterology in Havana, Cuba in adult patients of both sexes in whom chromoendoscopy was carried out with red phenol at 0.1% over the gastric mucosa for the detection of Helicobacter pylori infection between November 2008 and December 2010. The staining with red phenol at 0.1% is included in the invasive tests for the diagnosis of Helicobacter pylori infection and of the reactive techniques. The sensibility of red phenol dye in the diagnosis of Helicobacter pylori infection in the patients studied was of 72.6% with a confidence interval (C.I.) of 95% (64.9 to 79.2%) and a specificity of 75.5% C.I. 95% (61.9 to 85.4%). The positive predictive value was of 89.8% C.I. 95% (83.1 to 94.1%) and the negative predictive value of 48.1% C.I. 95% (37.3 to 59.0%). The proportion of false positives was of 24.5% C.I. 95% (14.6 to 38.1%)and the proportion of false negatives was of 27.4% C.I. 95% (20.8 to 35.1%). The diagnostic accuracy of the dye on the patients studied was 73.3% C.I. 95% (66.7 to 79.0%). The diagnostic odds ratio was 8.17 C.I. 95% (3.88 to 17.23), the J Youden ratio of 0.5 and the Kappa coefficient of 0.40 C.I. 95% (0.27 to 0.54). The staining dye with red phenol at 0.1% resulted in a useful method in the diagnosis of Helicobacter pylori infection in the gastric mucosa, it can be applied in our environment and has multiple advantages (topographic localization, avoids contamination and fast and immediate reading).

Cromoendoscopia con rojo fenol en el diagnóstico de la infección por Helicobacter pylori / Chromoendoscopy with red phenol in the diagnosis of Helicobacter pylori infection

Se realizó un estudio analítico de validación de prueba diagnóstica a pacientes adultos de ambos sexos, en el Instituto de Gastroenterología de La Habana. Cuba, a los cuales se les realizó cromoendoscopia con rojo fenol al 0,1% sobre la mucosa gástrica para la detección de infección por Helicobacter pylori, entre noviembre de 2008 y diciembre de 2010. La tinción con rojo fenol al 0,1% se encuentra dentro de las pruebas invasivas para la detección de la infección por H. pylori y de las llamadas técnicas reactivas. La sensibilidad de la tinción con rojo fenol en el diagnóstico de la infección por Helicobacter pylori en los pacientes estudiados fue del 72,6%. IC 95% (64,9 a 79,2%) y la especificidad del 75,5%. IC 95% (61,9 a 85.4%). El valor predictivo positivo fue del 89,8%. IC 95% (83,1 a 94,1%) y el valor predictivo negativo del 48,1%. IC 95% (37,3 a 59,0%). La proporción de falsos positivos fue de 24,5%. IC 95% (14,6 a 38,1%) y la proporción de falsos negativos de 27,4%. IC 95% (20,8 a 35,1%). La exactitud diagnóstica de la tinción en los pacientes estudiados fue del 73,3%. IC 95% (66,7 a 79.0%). La odds ratio diagnóstica fue de 8,17 IC 95% (3,88 a 17,23), el índice J de Youden de 0,5 y el índice de Kappa de 0,40 IC 95% (0,27 a 0,54). La tinción con rojo fenol al 0,1% resultó un método útil en el diagnóstico de la infección por Helicobacter pylori en la mucosa gástrica, aplicable en nuestro medio al contar además con múltiples ventajas (localización topográfica, evita contaminación y lectura rápida e inmediata)(AU)

An analytic study to validate a diagnostic test was carried out at the Institute of Gastroenterology in Havana, Cuba in adult patients of both sexes in whom chromoendoscopy was carried out with red phenol at 0.1% over the gastric mucosa for the detection of Helicobacter pylori infection between November 2008 and December 2010. The staining with red phenol at 0.1% is included in the invasive tests for the diagnosis of Helicobacter pylori infection and of the reactive techniques. The sensibility of red phenol dye in the diagnosis of Helicobacter pylori infection in the patients studied was of 72.6% with a confidence interval (C.I.) of 95% (64.9 to 79.2%) and a specificity of 75.5% C.I. 95% (61.9 to 85.4%). The positive predictive value was of 89.8% C.I. 95% (83.1 to 94.1%) and the negative predictive value of 48.1% C.I. 95% (37.3 to 59.0%). The proportion of false positives was of 24.5% C.I. 95% (14.6 to 38.1%) and the proportion of false negatives was of 27.4% C.I. 95% (20.8 to 35.1%). The diagnostic accuracy of the dye on the patients studied was 73.3% C.I. 95% (66.7 to 79.0%). The diagnostic odds ratio was 8.17 C.I. 95% (3.88 to 17.23), the J Youden ratio of 0.5 and the Kappa coefficient of 0.40 C.I. 95% (0.27 to 0.54). The staining dye with red phenol at 0.1% resulted in a useful method in the diagnosis of Helicobacter pylori infection in the gastric mucosa,it can be applied in our environment and has multiple advantages (topographic localization, avoids contamination and fast and immediate reading)(AU)