OBJECTIVE: Patient-reported symptom severity measures are important for evaluating the effectiveness of treatments for gastrointestinal diseases because they are the only measures in clinical evaluation that directly reflect the patient experience. Gastroparesis refers to abnormal gastric emptying, encompassing a variety of upper gastrointestinal symptoms which are difficult to quantify. The purpose of this study is to describe the development and initial testing of a new self-report measure, the Patient Assessment of Upper GastroIntestinal Disorders-Symptom Severity Index (PAGI-SYM) in subjects with gastroparesis. METHODS & RESULTS: Instrument content was based on a review of the published literature and patient and clinician interviews. The 37-item PAGI-SYM is comprised of 6 subscales: heartburn, reflux/regurgitation, nausea/vomiting, abdominal pain, bloating/early satiety, and other symptoms. Psychometric evaluation of the PAGI-SYM in 120 subjects with gastroparesis identified through 6 clinical sites in the US is currently being completed. Subjects complete the PAGI-SYM, the SF-36, and a measure of patient-rated change in gastroparesis-related symptoms, the Overall Treatment Effect Scale (OTE), by way of telephone interview. Two-week reproducibility will be evaluated in 30 subjects. The PAGI-SYM will be analyzed for internal consistency reliability, reproducibility, and validity. 104 subjects have been enrolled in the study to date. Data collection is proceeding with data analysis to be completed by October 1. CONCLUSION: The results of this study will provide valuable information on the psychometric properties of the PAGI-SYM.