Systematic review of patient-reported outcome instruments for gastroesophageal reflux disease symptoms.

Gastroesophageal reflux disease (GERD) symptoms are best assessed using patient-reported outcome (PRO) instruments. Guidance on developing well-defined and reliable instruments that capture optimal information from the patient's perspective was recently published by the US Food and Drug Administration and the European Medicines Agency. The aim of this systematic review was to identify and evaluate existing PRO instruments for GERD symptoms with regard to regulatory requirements. Systematic literature searches were conducted in PubMed and Embase to identify PRO instruments for GERD symptoms that have undergone psychometric evaluation. Content, construct and test-retest reliability, internal consistency, and responsiveness were evaluated in relation to regulatory recommendations. Supplementary searches were conducted to assess whether identified instruments had been used as clinical trial endpoint measures. The systematic literature searches identified 15 PRO instruments for GERD symptoms that have undergone psychometric evaluation. Eight were designed to evaluate GERD symptoms, two were to diagnose GERD, four were designed for both evaluative and diagnostic purposes, and one was designed for screening purposes. Five instruments were developed and reported to include most steps recommended by the Food and Drug Administration and European Medicines Agency, and have also been used as endpoint measures in clinical trials: the GERD Symptom Assessment Scale, the Nocturnal Gastro-oesophageal Reflux Disease Symptom Severity and Impact Questionnaire, the Reflux Questionnaire, the Reflux Disease Questionnaire, and the Proton pump inhibitor Acid Suppression Symptom test. Existing PRO instruments for GERD do not meet all the regulatory requirements for an outcome instrument in reflux trials and may need further validation.