Wahlqvist, Peter; Guyatt, Gordon H.; Armstrong, David; … - In: PharmacoEconomics 25 (2007) 5, pp. 385-396
Background: A validated productivity questionnaire, the Work Productivity and Activity Impairment questionnaire for Gastroesophageal Reflux Disease (WPAI-GERD), exists for Swedish patients with GERD. Objective: To assess responsiveness to change of the WPAI-GERD and construct validity of the...
