[Validation of the "Digest Questionnaire" for consistency and reproducibility with reference to upper abdominal...

"Digest" is a international effort to record the prevalence of digestive symptoms in the general population. The international questionnaire was tested in German translation for reliability and reproducibility. The questionnaire consists of 14 symptoms, which were investigated by standardized questions. Each symptom was described in 3 dimensions: frequency, severity and impact on daily activities. 127 successive patients referred for upper gastrointestinal endoscopy were interviewed twice by a young assistant and by an experienced gastroenterologist before the diagnostic work-up. A further 72 volunteers served as a control group. In these volunteers no upper gastrointestinal endoscopy was performed. Reliability and reproducibility were calculated by the Spearman rank test. The most frequent diagnoses were: organic diseases (oesophagitis [28], gastric ulcer/erosive gastritis [32] and duodenal ulcer [18]); functional diseases (dyspepsia [32] and irritable bowel syndrome [14]). Reproducibility was satisfactory by accepted standards (p > 0.7). Reliability was very good, with r-values for each symptom between p 0.96-0.99. The impact on daily activities was highest in the case of heart-burn or localized upper gastrointestinal pain, and lowest in the case of belching and fullness. The questionnaire can be easily administered by the non-specialist and the results discriminate well between functional/organic diseases and healthy people, thanks to excellent reproducibility and reliability.