NICE 2017 intrapartum fetal CTG interpretation guidelines- Examining its
reliability among clinicians: A prospective observational study
Abstract
Objective: Evaluation of the inter-observer and intra-observer agreement
for CTG interpretation by NICE guidelines 2017. Design: A hospital-based
Prospective observational study. Setting: The study was conducted at a
university teaching hospital Sample size: A total of 165 CTG tracings
from 165 laboring women were included in the study for interpretation by
6 clinicians with varying levels of experience in the specialty.
Methods: 6 clinicians (3 consultants & 3 residents in training)
independently interpreted CTG traces using NICE 2017 guidelines twice
with a locking period of 3 months between 2 interpretations. Main
outcome measure: Fleiss’s kappa and Cohen’s kappa coefficient was
employed for ascertaining interobserver and intraobserver agreement
using SPSS statistical software. Results: Among all CTG parameters,
observed agreement for baseline fetal heart was substantial
[k=0.678(0.677-0.679), p<0.0001] but the congruence for
variability was only slightly above the chance [0.185 (0.184-0.186),
p<0.0001]. Overall kappa coefficient was 0.382 (0.381-0.383)
with a p<0.0001 (moderate agreement) for classifying the CTG
category. The intra-observer agreement of most senior consultant for
baseline was nearly perfect (Kf=0.937) as compared to a kappa
coefficient of 0.367 of the junior-most resident. Conclusions: Different
CTG interpretation parameters were observed to have varying levels of
agreement among clinicians. Where experience was witnessed to improve
the agreement, the higher degree of non-congruence in certain CTG
parameters like variability, and type of decelerations may perhaps point
to the need for further objectivity in defining these parameters.