Abstract
A heartburn-specific quality of life instrument was developed using an approach which involves several steps: generating and selecting items, pretesting, reproducibility testing, and validity testing. These last two steps were performed in a randomized, double blind, placebo-controlled, six-week clinical trial evaluating ranitidine 150 mg twice daily on the clinical, economic, and humanistic outcomes of patients with gastroesophageal reflux disease. Reliability, content validity, and construct validity were assessed. Scales had high values for Cronbach's alpha and item to scale and scale to scale correlations were as predicted. The SF-36® questionnaire was administered to patients in this trial, and results provided further evidence of validity for the heartburn-specific quality of life instrument. The instrument development and validation process used in this trial can serve as a model to researchers who wish to assess quality of life in a clinical trial. The pragmatic approach used produced an instrument that is both reliable and responsive, with characteristics of a valid instrument.
Get full access to this article
View all access options for this article.