Trends in Diagnoses After Implementation of the Chicago Classification for Esophageal Motility Disorders (V3.0) for High-Resolution Manometry Studies at a Large Academic Medical Center

Abstract

Introduction: High resolution esophageal manometry (HRM) is considered the gold standard diagnostic test for esophageal motility disorders. The Chicago Classification (CC V3.0) is a hierarchical approach to interpret HRM studies and defines metrics for the diagnosis of esophageal motility disorders. The real world clinical practice impact of using CC V3.0 is unknown. The objective of this study was to determine the diagnostic distribution of esophageal motility disorders before and after implementation of CC V3.0 for HRM interpretation.Table 2: Rate Ratios for Diagnoses associated with Implementation of Chicago Classification V3.0 (09/01/2014)Methods: This was a retrospective analysis of patients with a HRM study conducted at a single center from January 1, 2013 through September 30, 2015. The implementation of CC V3.0 occurred in September 2014 and was fully adopted by December 2014. Patient charts were reviewed to extract demographics (age, sex), clinical variables (symptoms, indications), and HRM variables (esophageal pressure topography metrics, diagnoses and interpretation). If a diagnosis was not clearly stated, it was categorized as indeterminate. Rate ratios (RR) for CC V3.0 diagnostic categories (normal, indeterminate, achalasia and EGJ outflow obstruction (EGJOO), and major and minor motility disorders) were calculated by Poisson regression associated with the period after CC V 3.0 implementation. All models were adjusted for age and sex, and the reference time period was quarter 1 (Jan-Mar 2013). Results: There were 796 HRM studies included in the study. The mean ± standard deviation patient age was 53.4 ±15.5 years, with 59% being female (Table 1). The graphical trends in diagnoses over time are shown in Figure 1. The percentage of indeterminate and major motility disorder diagnoses was significantly lower in the time period after CC V 3.0 implementation. The percentage of normal, EGJOO, and minor motility disorder diagnoses were significantly higher post implementation. There was no change in the % of achalasia diagnoses.Figure 1Table 1: Characteristics of the study population overall, and by time periods before and after Chicago Classification V3.0 policy implementation on 09/01/2014Conclusion: This is one of the first studies showing the impact of CC V3.0 on HRM interpretation in clinical practice. The increase in the number of normal studies and decrease in the number of indeterminate studies suggests that CC V3.0 clarifies the criteria for a normal study. The increase in studies with a diagnosis of EGJ outflow obstruction may reflect the heterogeneity of disorders with clinically relevant outflow obstruction. Further study is needed to determine if these results translate to changes in therapeutic decision making and treatment outcomes.