Objectives Gastroesophageal reflux is common in infants and gastroesophageal reflux disease (GERD) is a clinical diagnoses. GERD is a pathologic process in infants, manifested in poor weight gain, esophagitis, persistent respiratory symptoms and/or neurobehavioral changes. It is estimated that GERD occurs in 1 in 200-300 infants. How many infants that are possibly over diagnosed with GERD in Denmark is not known.

Method This is a cross-sectoral study between general practice and pediatric department Slagelse Hospital, Zealand, Denmark. We used data from the birth registry and the prescribed drug register (Lægemiddelregisteret) for estimating the prevalence of GERD and overdiagnosis. There is no inclusion of CRP numbers. An approval for ethical committee is not needed.

Results In the year of 2021 a total of 63710 babies were born. Using the occurrence of GERD at 1:2-300 we estimated that approximately 212-319 (0,03%-0,05%) infants born in 2021 could possibly be affected by GERD. Using the prescribed drug register there are 1.375 (2%) infants from 0-12 months that have been prescribed anti-acid medication at some point during that year.

Conclusions There are indications for antacid overtreatment of infants and that might be a result of overdiagnosing GERD in Denmark. However further research is needed to confirm these results.