Does the pHoenix score reduce the inconclusive GERD diagnosis: a net reclassification index analysis

Area of Science:

• Gastroenterology
• Diagnostic Medicine
• Medical Technology

Background:

• Acid exposure time (AET) provides inconclusive results in 10-15% of patients undergoing multichannel intraluminal impedance-pH (MII-pH) monitoring for suspected gastroesophageal reflux disease (GERD).
• This diagnostic uncertainty delays GERD diagnosis and management.
• The pHoenix score (pHx-s) was developed to address this uncertainty, but its performance in Latin American populations is unknown.

Purpose of the Study:

• To evaluate the performance of the pHoenix score (pHx-s) in a Latin American cohort undergoing MII-pH monitoring for suspected GERD.
• To assess the pHx-s's ability to reduce inconclusive diagnostic results compared to traditional Acid Exposure Time (AET) criteria.
• To compare the diagnostic accuracy of pHx-s against the DeMeester score as a reference standard.

Main Methods:

• Retrospective cohort analysis of symptomatic adults who underwent high-resolution manometry, MII-pH, and upper endoscopy.
• Calculation of pHx-s using upright and supine AET.
• Diagnostic performance metrics including Area Under the Curve (AUC), sensitivity, and specificity were determined, with the DeMeester score as the reference.

Main Results:

• The study included 292 patients, with a median age of 61 years and 71.2% females; 79.1% had hiatal hernia (HH).
• pHx-s demonstrated excellent diagnostic performance with an AUC of 0.98.
• pHx-s reduced inconclusive results from 13.0% to 4.1% (a 68.5% reduction), with a Net Reclassification (NR) improvement of 14.6%.

Conclusions:

• The pHoenix score (pHx-s) significantly reduces inconclusive GERD diagnoses in a Latin American cohort, even with a high prevalence of hiatal hernia.
• pHx-s exhibits excellent diagnostic performance comparable to the DeMeester score.
• These findings support the utility of pHx-s in diverse clinical settings for improving GERD diagnosis.