Development and validation of a cross-cultural questionnaire to evaluate nonulcer dyspepsia: the Porto Alegre Dyspeptic Symptoms Questionnaire (PADYQ)

Abstract

Despite its high prevalence, nonulcer dyspepsia is still difficult to study, due to the lack of adequate tools to measure significant outcomes. The objective of this study was to develop and validate a symptom-focused, disease-specific questionnaire to evaluate patients with nonulcer dyspepsia. For that, the questionnaire was carefully written following widely accepted terminology, so as to facilitate translation and validation in other languages and cultures. The questionnaire was developed using Rome I terminology for symptoms, which were evaluated according to their intensity, duration, and frequency when applicable. Thirty-one patients with nonulcer dyspepsia, as well as 31 sex-and age-matched volunteers without digestive problems were used to assess the internal consistency, reproducibility, responsiveness, content validity, and discriminant validity of the questionnaire. Another 31 functional dyspeptic patients were enrolled for assessment of criterion validity. Cronbach's alpha coefficient was 0.82. The intraclass correlation coefficient for the scores obtained 7 days apart was 0.86. The mean score obtained after 3 months of treatment was 16.4, vs. 23.03 at baseline (P = 0.001). Two blinded gastroenterologists agreed that the questionnaire adequately evaluated nonulcer dyspepsia. The median symptoms score for controls was 0, vs. 22.5 for dyspeptic patients (P = 0.001). An inverse correlation was observed between quality of life and dyspeptic symptoms (R = -0.28, P = 0.026). The proposed questionnaire has high degrees of both reproducibility and responsiveness. As this questionnaire was based on Rome I International Consensus terminology, it is expected that it will be easy to translate and validate.