RESUMEN
OBJECTIVES: To evaluate the referral patterns and indications for esophageal pH monitoring in an open-access system and to determine whether these indications conform to practice guidelines of the American Gastroenterological Association (AGA). METHODS: A total of 851 consecutive patients referred for ambulatory pH monitoring to nine open-access gastrointestinal units over a 12-month period received a structured interview. The indication for the examination was decided by the physician performing the procedure, on the basis of the patient's clinical history and main complaint. RESULTS: Three hundred and twenty-three (38%) examinations were for indications in accordance with the guidelines. The proportion of appropriate requests in each center ranged from 34% to 47%. This figure was not significantly different in larger gastrointestinal units (more than 150 examinations per year) and smaller ones (35% and 40%; p= 0.14). The proportion of appropriate requests was 45% for gastroenterologists, 38% for surgeons, 32% for other specialists, and 24% for primary care physicians (PCPs) (p < 0.001). The percentage of appropriateness was significantly different between gastrointestinal specialists and PCPs (p < 0.001 vs gastroenterologists, p= 0.015 vs GI surgeons), and between gastroenterologists and other specialists (p= 0.006). The underuse of an empirical trial of acid-suppression therapy in patients with suspected reflux disease and the overuse of this test to confirm a diagnosis in patients with erosive esophagitis and in endoscopy-negative cases with typical symptoms responding completely to antisecretory therapy accounted for most of the referrals, which was not in accordance with the guidelines. CONCLUSIONS: In an open-access system, a high proportion of esophageal pH studies are done for indications not consistent with published guidelines, particularly among the examinations not requested by gastrointestinal specialists. Further education is still needed on the appropriate use of esophageal pH monitoring and management of gastroesophageal reflux disease (GERD).