Intra- and Inter-Observer Variability in the Assessment of Intrapartum Cardiotocograms

Abstract

The diagnostic value of a test depends on the variabilityof thetest resultsand theaccuracyofthe test. Theobject of this investigation was to estimate the observer variability and the accuracy, when intrapartum CTGs were assessed by experienced obstetricians. Fifty CTGs were evaluated twice by four obstetricians. They were asked to identify the CTGs belonging to the compromised infants. They were told the criteria for a compromised infant and the incidence (one-third).Eleven (22%) of the CTGs were assessed in the same way of all the Obstetricians in both evaluations. Between the obstetricians, thc accuracy ranged from 50 to 66%. We conclude that the considerable observer variability found in this and other invcstigations must severely impair the clinical value of electronic fetal monitoring (EFM). The variability must be reduced before the "true" predictive value and thecost/benefit of EFM can be estimated. Key worclr: Fetal monitoring, delivery, asphyxia neonatorumT h e value of electronic fetal monitoring (EFM) during delivery has been assessed in several investigations designed with random allocation and controls. Also the latest and largest (1) has only been able t o show a marginal effect of intrapartum EFM.Peter Vest Nielsen, M.D. Akanderhaven 118 DK -2965 Smerum Denmark Acco Obstet Gynecd S a n d 66 11987)

Assessment of STAN S21 fetal heart monitor by medical staff

“…Respondents in that study called attention to the difficulty of CTG interpretation during labor and showed mixed satisfaction, with some midwives skeptical of its advantages. Another study similarly showed a demand for an alternative to CTG surveillance to counter the difficulty in its interpretation and strong intraand inter-operator variability [8].…”

Rythme cardiaque fœtal pendant le travail : définitions et interprétation

“…L'analyse et l'interprétation des anomalies du RCF restent (très) variables selon les observateurs, de même que pour le même observateur en fonction du temps ou a posteriori après connaissance de l'issue néonatale [19,20] (NP2).…”

Hypoxémie, chémorécepteurs périphériques et rythme cardiaque fœtal

“…Néanmoins, cette méthode de surveillance reste largement répandue parce qu'elle présente certains avantages dont la traçabilité et la possibilité de structurer les indications des prélèvements au scalp foetal [3,4]. L'incapacité de l'ERCF pour prédire l'acidose foetale est pour une part en relation avec un défaut d'interprétation cohérente et systématique des tracés [5] : en effet, les mauvais scores de la concordance d'interprétation interet intra-observateurs laissent peser un sérieux doute sur la qualité de l'analyse telle qu'elle est assumée par différents intervenants dans les études observationnelles rétrospec-tives [6,7].…”