Given a passage, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.
Q: Pathophysiological mechanisms associated with neoplastic progression in patients with short-segment Barrett's oesophagus (SSBO), who represent the vast majority of the Barrett population, have not been defined.", 'To evaluate pathophysiological characteristics of patients with SSBO and dysplasia detected at 3-year surveillance endoscopy (incident dysplasia).', 'Patients with SSBO underwent impedance-pH monitoring during heartburn-suppressing PPI therapy. Fifteen patients (12 males, median age 62 years) with incident dysplasia and 50 patients (43 males, median age 59 years) without dysplasia were compared. Impedance-pH parameters, including chemical clearance assessed by the post-reflux swallow-induced peristaltic wave (PSPW) index, were evaluated.', 'All patients declared persisting heartburn suppression on maintenance PPI therapy at 3-year follow-up, 58/65 (89%) with standard dosages. The median gastric and oesophageal acid exposure time (GAET and OAET) did not differ between patients with and without incident dysplasia at the time of surveillance (36% and 0.6% vs. 33% and 0.5%) or index endoscopy (33% and 0.3% vs. 41% and 0.5%) (P > 0.05). Contrastingly, the median PSPW index was significantly lower in patients with than in patients without incident dysplasia at the time of surveillance (15%, vs. 32%) and index endoscopy (12% vs. 30%) (P = 0.001). The PSPW index, the GAET and the OAET did not vary over time (P > 0.05). A PSPW index <26% was predictive of incident dysplasia with a 75% accuracy.
A:
Is neoplastic progression in short-segment Barrett 's oesophagus associated with impairment of chemical clearance , but not inadequate acid suppression by proton pump inhibitor therapy?