No single test identifies reflux as the etiology for extra-esophageal symptoms.
It is well recognized that reflux can be causal in subgroups of patients with chest and ENT symptoms like asthma, cough, hoarseness, sore throat, sinusitis, and ear pain. However, the possibility of reflux as the cause for a variety of ENT symptoms is both overestimated and often abused. In fact, the cause of extraesophageal symptoms in many patients is actually often multifactorial. One main point with the association between reflux and ENT symptoms, is this diagnosis cannot be applied on a global basis. Each patient must be looked at on a case-by-case basis, using a compendium of evidence as well as clinical acumen. This data can include symptom sets, response to medication, ENT evaluation, and endoscopy. The role of diagnostic testing in this group is to establish presence and degree of reflux and assess the likelihood that it may be linked to the patients symptoms. No single test definitively identifies reflux as the sole etiology for any specific extra-esophageal symptoms. An ENT evaluation showing pharyngitis does not automatically equate to reflux. An endoscopy also does not rule it in either, even if features of reflux are seen.
See the AGA’s Clinical Guidelines on Extraesophageal Symptoms and Diseases Attributed to GERD here.