Objective: To develop a questionnaire to measure gastroesophageal reflux disease in the community and to test its reliability and validity.
Material and methods: The reliability of the questionnaire was measured by a test-retest procedure in 38 outpatients and 77 community residents 25 to 74 years of age, whereas concurrent validity was evaluated by comparing findings from a physician interview with self-report data from 51 patients. For statistical analysis of the reliability of each question, the kappa statistic and the 95% confidence interval were calculated.
Results: The questionnaire was easy to understand and well accepted. The reliability (median kappa for outpatients, 0.70 [interquartile range, 0.59 to 0.81]; median kappa for population sample, 0.70 [interquartile range, 0.60 to 0.81]) and validity (median kappa, 0.62 [interquartile range, 0.49 to 0.74]) were acceptable.
Conclusion: Our initial results suggest that this questionnaire is valid and should be applicable in population-based studies to assess gastroesophageal reflux disease.