Learners favour high resolution oesophageal manometry with better diagnostic accuracy over conventional line tracings

Abstract

Background: High resolution manometry (HRM) provides a colourful representation of oesophageal motility. Novice and intermediate learners were tested to compare HRM Clouse plots and conventional manometry for accuracy, ease of interpretation and knowledge retention.

Methods: 36 learners evaluated 60 randomised motility sequences (30 HRM Clouse plots with corresponding line tracings) 4 months apart, following a tutorial. Learners rated prior knowledge of oesophageal pathophysiology and manometry and scored ease and speed of interpretation on 10 cm visual analogue scales (VAS).

Results: Understanding of oesophageal pathophysiology was low in all cohorts (2.9±0.4 on VAS) and knowledge of HRM and conventional motility studies was even lower (1.9±0.4 and 1.8±0.3, respectively, p=NS). After the tutorial, diagnostic accuracy was significantly higher with HRM Clouse plots than with line tracings (p<0.001). HRM gains in diagnostic accuracy were evident over line tracings (43.1%), particularly with aperistalsis (36.1%), oesophageal body hypomotility (25.8%) and relaxation of the lower oesophageal sphincter (21.0%) (p<0.001 for each comparison); these were maintained at the second evaluation. Gains were independent of academic level (F=0.56, p=0.5) and did not correlate with prior experience of learners (r=-0.18, p=0.29). Learners favoured HRM Clouse plots (80.6%) over line tracings and reported faster interpretation (94.4%).

Conclusions: HRM Clouse plots provide ease of interpretation that translates into higher diagnostic accuracy and better knowledge retention in novice and intermediate learners of oesophageal manometry. These results implicate the value of pattern recognition in HRM interpretation, irrespective of academic level and prior understanding of oesophageal motor function.

Figure 1

Comparison of understanding of oesophageal motor pathophysiology, oesophageal motility interpretation in terms of line tracings and high resolution manometry (HRM) prior to the tutorial provided as part of the study. Although gastroenterology fellows reported higher values for all categories, only their self-reported prior understanding of HRM was statistically higher than the other groups. Data are shown as mean±SEM values from the 10 cm visual analogue scale (*p<0.05).

Figure 2

Percentage gain in diagnostic accuracy of high resolution manometry (HRM) over line tracings, for each of the two evaluations performed. Gains were consistently seen across motor patterns. Incremental gains seen at the second evaluation suggest more prominent decline in diagnostic accuracy of line tracing interpretation over the 4-month interval between evaluations. LES, lower oesophageal sphincter.

Figure 3

Comparison of learner preference of high resolution manometry (HRM) versus line tracings in terms of ease and speed of interpretation. These were assessed using visual analogue scales (VAS), anchored by line tracings at one end and HRM on the other, which were depicted horizontally on the actual questionnaire. Data are shown as median values and IQR on the 10 cm VAS scales.