This international collaboration assessed 32 papers which had published original data on the experimental, diagnostic, treatment or prognostic association between GORD and CRS. The study aims to systematically review the evidence for a role of GORD in CRS. Case control, crossover, cohort, RCT studies were all included provided that they included original data. A PRISMA flow diagram is provided to explain study selection. There were 968 publications found which were reduced to 32 which met inclusion criteria, further increased to 33 since one paper included two studies. All studies were grouped in three ways: pathogenic or etiological role of GORD in CRS (21); epidemiological association between GORD and CRS (8) and prognostic interaction between them (4). The results from each paper are discussed in detail, they show that there are multiple associations between GORD and CRS. H pylori is prevalent in sinonasal tissue in CRS and pepsin is present in sinonasal aspirates. Epidemiologically, CRS is more prevalent in GORD sufferers. Prognostic evidence around GORD in failure of FESS procedures is conflicting. The authors conclude that there are multiple associations between GORD and CRS and this should be considered, particularly in patients with recalcitrant CRS.
