A comparison of visual and automated methods of analyzing fetal heart rate tests

Abstract

Our objective in this study was to compare evaluation and clinical implications of visual versus computerized analysis of nonstress tests. Nonstress tests of 575 high-risk patients were analyzed visually and by a computer using the Oxford Sonicaid System 8000. Standard reactivity criteria were used for visual assessment; the System 8000 used an algorithm with the Dawes-Redman criteria. Ninety-six percent of nonstress tests that met Dawes-Redman criteria were reactive by visual analysis; 93% of reactive nonstress tests met Dawes-Redman criteria. Only 30% of tests that failed Dawes-Redman criteria were nonreactive, whereas 44% of nonreactive tests failed to meet Dawes-Redman criteria. Sensitivities, specificities, and positive and negative predictive values were similar for both approaches. Additional tests or interventions would have occurred in 9% of the cases analyzed by System 8000 and in 49% of the cases analyzed visually. Although these approaches rate nonstress tests differently, their diagnostic performances are similar. Automated fetal heart rate testing may become an acceptable alternative to conventional visual analysis.