The Hong Kong index of dyspepsia: A validated symptom severity questionnaire for patients with dyspepsia

Aim: Locally validated symptom questionnaires are essential instruments in dyspepsia research. A symptom score for Chinese dyspeptics was developed. Multiple aspects of validity and reliability were assessed. Methods: Sixty-five patients with endoscopy-negative dyspepsia and 65 healthy controls were presented with a list of 24 previously determined common abdominal symptoms and asked to rate the severity in a five point Likert scale. Comprehensibility and relevance of symptoms were assessed. The questionnaire was administered 3 h later to assess for reproducibility. A locally validated Short Form-36 quality-of-life questionnaire was also administered. Cisapride 5 mg thrice daily was prescribed to dyspeptic patients but not to the controls. The dyspepsia symptom and SF-36 questionnaires were repeated after 3 weeks for patients under treatment. Global change in symptoms and the need for further medical care were assessed. Concept, content, construct and criterion validity, consistency and reproducibility of the dyspepsia symptom questionnaire were assessed. Results: All items were considered comprehensible by more than 90% of subjects. Relevance of individual symptoms to dyspeptic patients ranged from 10.8-76.9%. Twelve items were selected by logistic regression to account for most of the differences between control and dyspeptic patients. Test-retest reproducibility and internal consistency were good with the intraclass correlation coefficient of 0.89 and Cronbach's alpha coefficient of 0.90. A cut-off score of equal to or greater than 16 was determined to discriminate between controls and dyspeptic patients. The dyspepsia score correlated negatively with all domains of the SF-36 quality of life scale except physical functioning. The dyspepsia questionnaire also discriminated between patients who reported a subjective improvement in symptoms and those who reported no change or worsening. Conclusions: The dyspepsia symptom index was easy to understand, internally consistent and reproducible. It predicted global symptom change, and the symptom severity scores correlated negatively with quality of life.