Validation of phone interview for follow-up in clinical trials on dyspepsia: evaluation of the Glasgow Dyspepsia Severity Score and a Likert-scale symptoms test

Objective To validate two widely used dyspepsia scores performed by phone i nterview. Design Spanish translations of the Glasgow Dyspepsia Severity Score and a L ikert-scale symptomatic test were evaluated. Responsiveness to the treatmen t, validity of the tests, and reproducibility of tests performed by phone i nterview were assessed. Setting Gastroenterology and endoscopy unit of a county hospital. Participants Group I consisted of 16 ulcer patients undergoing Helicobacter pylori eradication; Group II consisted of 29 healthy volunteers; and Group III consisted of 95 patients undergoing upper endoscopy. Measurements Glasgow Severity Dyspepsia Score and Likert test. Results Both tests showed adequate improvement (responsiveness) after H. py lori eradication. With regard to validity, the Glasgow and Likert test were significantly higher in 95 patients undergoing endoscopy than in 29 health y controls. Analysis of reproducibility showed that intraobserver variation was low on both the Glasgow and Likert scores. No differences were found b etween consecutive tests regardless of whether both were performed by phone (24 patients) or one by phone and the other by clinical interview (40 pati ents). Interobserver variation analysis showed that the Glasgow test remain ed highly reproducible even when performed by different observers using dif ferent methods (clinical interview 8.83, phone 8.44, P = 0.12). By contrast , Likert-scale tests showed significant differences between observers for a ll symptoms except abdominal pain. Conclusions (1) The Glasgow score is highly reproducible even when performe d by different observers and using different methods. (2) By contrast, Like rt tests show greater variability. To be reproducible in different conditio ns, they need to be performed by the same observer. (C) 2000 Lippincott Wil liams & Wilkins.