Context: Validated questionnaires are essential tools to be utilized in epidemiological research. At the moment there are no Rome III diagnostic questionnaires translated to Portuguese.
Objective: To validate the Portuguese version of the Rome III Diagnostic Questionnaire for Functional Dyspepsia.
Methods: The questionnaire has been translated following the Rome III recommendations. Hundred and nine consecutive patients with functional dyspepsia answered the questionnaire. The control group comprised 100 healthy consecutive blood donors, without digestive problems. Internal consistency, reproducibility, responsiveness, discriminate validity and content analysis were evaluated.
Results: Cronbach's α coefficient was 0.92. The questionnaire showed reliability: the patients answered it in a similar way on two distinct occasions and their responses were substantially very similar (P = 1.00). The questionnaire was able to demonstrate changes when they occur (P<0.01). Two "blinded" gastroenterologists agreed that the questionnaire adequately evaluated Functional Dyspepsia. When we compared the answers between patients and controls, the questionnaire showed that 5.3% of controls had Functional Dyspepsia symptoms compared with 91.2% of the patients (P<0.01).
Conclusion: The Rome III Diagnostic Questionnaire for Functional Dyspepsia is ready to be used in clinical researches in lusophone countries, as it has been successfully validated in Portuguese.