Fetal biometry in ultrasound: A new approach to assess the long-term impact of simulation on learning patterns

CONTEXT

Simulation-based education (SBE) has demonstrated its acceptability and effectiveness in improving ultrasound training. Because of the high cost of its implementation (investment in equipment and supervision), a pragmatic assessment of the transfer of skills learned in SBE to clinical practice and the identification of its optimal scheduling conditions have been requested to optimize its input.

OBJECTIVES

To quantify the long-term impact of simulation-based education (SBE) on the adequate performance of ultrasound fetal biometry measurements (I). The secondary objective was to identify the temporal patterns that enhanced SBE input in learning (II).

METHODS

Trainees were arbitrarily assigned to a 6-month course in obstetric ultrasound with or without an SBE workshop. In the SBE group, the workshop was implemented 'before' or at an 'early' or a 'late-stage' of the course. Those who did not receive SBE were the control group. The ultrasound skills of all trainees were prospectively collected, evaluated by calculating the delta between OSAUS (Objective Structured Assessment of Ultrasound Skills) scores before and after the course (I). Concomitantly, the accuracy of trainees' measurements was assessed throughout the course by verifying their correlation with the corresponding measurements by their supervisors. The percentage of trainees able to perform five consecutive sets of correct measurements in the control group and in each SBE subgroup were compared (II).

RESULTS

The study included 61 trainees (39 SBE and 22 controls). Comparisons between groups showed no significant difference in the quantitative assessment of skill enhancement (difference in the pre- and post-internship OSAUS score: 1.09 ± 0.87 in the SBE group and 0.72 ± 0.98 in the control group) (I). Conversely, the predefined acceptable skill level was reached by a significantly higher proportion of trainees in the 'early' SBE subgroup (74%, compared with 30% in the control group, P<0.01)(II).

CONCLUSIONS

The quantitative assessment does not support the existence of long-term benefits from SBE training, although the qualitative assessment confirmed SBE helped to raise the minimal level within a group when embedded in an 'early' stage of a practical course.

[Skills assessment for the practice of fetal ultrasound biometry: Prospective validation of the OSAUS METHOD score]

OBJECTIVES

To develop and validate a customized variant for fetal biometry of the generic OSAUS score (Objective Structured Assessment of Ultrasound Skills) METHODS: The 5-points OSAUS METHOD grid was elaborated by defining five target skills specific to fetal biometry for each thematic item of the generic score. The level of skills of 43 trainees was prospectively assessed during an ultrasound examination by using this grid. The results of the "novice" level group (experience<10 ultrasounds) were compared to those of the "intermediate" level group (experience≥10 ultrasounds) (I). The reached/non-reached skills ratio within the different items composing the score allowed the identification of priority areas of improvement (II). Previously published distribution and actual distribution of ratings according to the generic pass/fail score were compared (III).

RESULTS

Median scores of "novices" (n=29) and "intermediates" (n=14) groups were statistically different, 1.87 (±0.75) and 3.31 (±0.83) (P=1.85-5), respectively and corresponded to the pre-existing experience (I). A lower ratio of reached skill allowed the identification of "documentation of the examination" item as a priority area of improvement for both groups (II). The relevance of the pass/fail score is consolidated, even if an overlap was observed between novices and intermediates groups (III).

CONCLUSIONS

The relevancy and feasibility of using OSAUS scoring method for fetal biometry are supported. In addition, the possibility of comparisons with generic OSAUS remains.

[Training in fetal ultrasound biometry: Prospective assesment of Objective Structured Assessment of Ultrasound Skills (OSAUS) efficiency]

BACKGROUND

Fetal biometry quality directly influences obstetrical care relevance. However, obstetrician proficiencies are heterogeneous in particular during initial training.

OBJECTIVES

To assess the predictive value of OSAUS scale to identify operators with enough command to perform a valid estimation of fetal weight (EFW) (I). This study also assesses OSAUS intra-operator inter-exams variability (II) and pass/fail score relevancy (III).

METHODS

Lecturers in Nancy University Hospital assessed trainees' proficiency for EWF systematically and prospectively through OSAUS scale. The trainee assessment was performed right after the one of the senior operator (reference EFW) on three consecutive patients during standard care ultrasounds. To ensure variability in proficiency within the sample, previous practice was taken into account during enrollment ("novices" and "intermediates" for<20 and 20 past exams, respectively). Correlation between mean OSAUS and validity of EFW (a valid EFW was defined by a difference with the reference EWF<0.8 Z-score) and variability between consecutive assessments were assessed.

RESULTS

The study population was constituted of 8 "novice" and 8 "intermediate" trainees. Association between OSAUS and EFW validity was significant (P<0.03) (I). Intra-operator inter-exams variability was majored in the "novice" group (coefficients of variation were 25% vs. 10% in "novice" and "intermediate" group respectively) (II). Within the sample, specificity and positive predictive value of a pass/fail score OSAUS>3.5 to predict EFW validity were 77% and 71%, respectively (III).

CONCLUSION

A 3.5 OSAUS pass/fail score could provide a relevant threshold to estimate operator proficiency in assessing fetal biometry in an autonomous and secure way.

Prospective assessment of reproducibility of three-dimensional ultrasound for fetal biometry

PURPOSE

To compare fetal ultrasound measurements performed by two observers with different levels of experience and evaluate the potential contribution of the use of three-dimensional (3D) ultrasound on repeatability, reproducibility and agreement of two-dimensional (2D) and 3D-derived measurements.

MATERIALS AND METHODS

Two observers (one senior and one junior) measured head circumference (HC), abdominal circumference (AC) and femur length (FL) in 33 fetuses (20 to 40 weeks of gestation). Each observer performed two series of 2D measurements and two series of 3D measurements (i.e., measurements derived from triplane volume processing). Measurements were converted into Z-scores according to gestational age. Variability between the different series of measurements was studied using Bland-Altmann plots and intra-class correlation coefficients (ICC).

RESULTS

Agreement with the 2D measurements of the senior observer was higher in 3D than in 2D for the junior observer (systematic differences of -0.4, -0.2 and -0.8 Z-score vs. -0.1, -0.1 and -0.6 for HC, AC and FL on 2D and 3D datasets, respectively). The use of 3D ultrasound improved junior observer repeatability (ICC=0.94, 0.88, 0.90 vs. 0.94, 0.94 and 0.96 for HC, AC and FL in 2D and 3D, respectively). The reproducibility was greater using the junior observer 3D datasets (ICC=0.75, 0.60 and 0.45 vs. 0.79, 0.89 and 0.63 for HC, AC and FL, respectively).

CONCLUSION

The use of 3D ultrasound improves the consistency of the measurements performed by a junior observer and increases the overall repeatability and reproducibility of measurements performed by observers with different levels of experience.