Validation of a Four-Graded Scale for Severity of Heartburn in Patients with Symptoms of Gastroesophageal Reflux Disease

Abstract

Objectives To evaluate the reliability, responsiveness, and validity of a four-graded symptom severity scale (none, mild, moderate, severe) and an eight-graded frequency scale (number of days with symptoms during past week) for assessment of heartburn severity and frequency in patients with symptoms of heartburn but without esophagitis. Methods Data were taken from two 4-week clinical trials comparing esomeprazole 20 mg and/or 40 mg to omeprazole 20 mg. Both scales were analyzed in terms of mean scores and treatment success rates, after dichotomization to “treatment success” variables. Results Heartburn severity reliability was higher when assessed by patient diary cards than by the investigator (intraclass correlation coefficients were 0.79 and 0.59, respectively; corresponding figures for heartburn frequency were 0.77 and 0.78). There was good agreement between investigator and diary card assessments for the dichotomized variables “complete resolution” and “adequate relief” from heartburn. High correlation between investigator- and diary card-assessed heartburn severity and frequency was apparent. Responsiveness was high, as shown by comparing 4-week treatment success rates to the patients' perception of treatment effect according to the Overall Treatment Effect questionnaire. Construct validity was good (kappa values approximately 0.70 for agreement between complete resolution and the dichotomized Gastrointestinal Symptom Rating Scale [GSRS] Heartburn item). Correlations between heartburn severity and frequency and the GSRS Heartburn item were similarly high. Conclusion The four-graded heartburn severity and eight-graded frequency scales are reliable, responsive, and valid when used in clinical trials of patients with symptoms of gastroesophageal reflux disease, irrespective of the type of assessment (investigator assessment or patient diary cards).