A cross-sectional comparison of three guidelines for intrapartum cardiotocography

Abstract

Objective: To compare the cardiotocography classification systems outlined by the International Federation of Gynecology and Obstetrics (FIGO) in 2015 and the UK National Institute for Health and Care Excellence (NICE) in 2007 and 2014.

Methods: A cross-sectional observational study of cardiotocography practices at a UK hospital was conducted among labor ward staff (n=21) from November 1 to November 31, 2015. All observers classified ten cardiotocography traces according to the three guidelines using a bespoke form. Outcome measures included interobserver agreement (κ values), percentage agreement, intervention rate, and perceived ease of use.

Results: The κ values were 0.38 (FIGO 2015), 0.37 (NICE 2007), and 0.34 (NICE 2014). The percentage agreement was identical across the three systems for both normal cardiotocography results (100.0%) and for intermediate or suspicious results (80.9%). By contrast, the percentage agreement for abnormal or pathological findings was 47.6% for NICE 2014, 76.2% for FIGO 2015, and 91.0% for NICE 2007 guidelines. Among 210 observations, intervention was deemed necessary for 48 (22.9%) for FIGO 2015, 29 (13.8%) for NICE 2014, and 56 (26.7%) for NICE 2007 guidelines. The FIGO 2015 system was considered the easiest to use by 13 (61.9%) observers.

Conclusion: Interobserver agreement of cardiotocography classification is suboptimal. The FIGO 2015 system offered favorable agreement scores, perceived ease of use, and a moderate intervention rate.

Keywords: Cardiotocography; Ease of use; Interobserver agreement; Intervention rate; Percentage agreement score.