Background: The primary diagnosis of functional dyspepsia (FD) is made on the basis of typical symptoms and by excluding organic gastrointestinal diseases that cause dyspeptic symptoms. However, there is difficulty reaching a diagnosis in FD.

Objectives: To assess the efficiency of the Usefulness Index (UI) test and history-taking in diagnosing FD.

Methods: A study on acute abdominal pain conducted by the World Organizati­on of Gast­roentero­logy Research Committee (OMGE) included 1333 patients presenting with acute abdo­minal pain. The clinical history-taking variables (n=23) for each pa­tient were recorded in detail using a prede­fined structured data collection sheet, and the collected data were compared with the final diagnoses.

Results: The most signifi­cant clinical history-taking variables of FD in univa­riate analysis were risk ratio (RR): location of pain at diagnosis (RR = 5.7), location of initial pain (RR = 6.5), previous similar pain (RR = 4.0), duration of pain (RR = 2.9), previous abdominal surgery (RR = 4.1), previous abdominal diseases (RR = 4.0), and previous indigestion (RR = 3.1). T­he sensi­tivity of the physicians’ initial de­cisi­on in detecting FD was 0.44, speci­fi­city 0.99 and effi­ciency 0.98; UI was 0.19 and RR 195.3. In the stepwise multivariate logistic regression analysis, the independent predictors of FD were the physicians’ initial decision (RR = 266.4), location of initial pain (RR = 3.4), duration of pain (RR = 3.1), previous abdominal surgery (RR = 3.7), previous indigestion (RR = 2.2) and vomiting (RR = 2.0).

Conclusions: The patients with upper abdominal pain initially and a previous history of abdominal surgery and indigestion tended to be at risk for FD. In these patients the UI test could help the clinician differentiate FD from other diagnoses of acute abdominal pain.