OBJECTIVE: Results from studies using patient-reported data in employed populations indicate that Gastroesophageal Reflux Disease (GERD) causes a reduction in productivity while at work of around 10%. The aim of this study was to assess if a link between GERD and reduced productivity while at work can be established by using objective measurements of hourly and annual at-work productivity. METHODS: We examined the Human Capital Management Services Research Reference database of employees where units-of-production are captured on a per-employee-per-day basis. ICD-9 Codes were used to distinguish employees with GERD from the non-GERD cohort. The index date in the GERD cohort was defined as the date of first diagnosis during 2001 or later, while the average GERD index date was used in the non-GERD cohort. Hourly and annual productivity were measured during the year following each employee's index date. Regression modelling was used to measure the productivity differences between employees with GERD and employees without GERD while controlling for age, marital status, race, full-time/part-time status, location, and comorbidity (Charlson Comorbidity Index). RESULTS: Data were available for 27,316 employees: 541 employees with GERD and a control group of 26,775 employees without GERD. The mean age of employees with GERD was 40 years, and 77% were full time employees. The analysis of at-work productivity show that GERD employees' average units processed were significantly lower by 4.4% hourly and 6.0% annually (P<0.05). CONCLUSIONS: Even though quality aspects of work productivity are not captured, objective productivity measurements from real work-output data (the number of units of work performed by each employee on a daily basis) show that GERD has a significant impact on productivity while at work. Interventions focused on managing GERD could increase work productivity and thus lead to benefits for the employee, the employer and society as a whole.