Salicylate use: a negative predictive factor for finding pathology explanatory for iron deficiency anaemia

Purpose: To determine whether the use of salicylates is a predictive factor for detecting explanatory pathology during gastroscopy or colonoscopy procedures in patients with iron deficiency anaemia (IDA). Methods: This retrospective study included patients who underwent a gastroscopy and/or a colonoscopy to determine the cause of IDA at Treant Healthcare, hospital location Scheper in Emmen, the Netherlands, between 2010 and 2016. The study compared two groups. The first group consisted of patients who were not taking antithrombotics at the time of, and during the last six months prior to, the endoscopy. The second group consisted of patients who used salicylates at the time of, and during the last six months prior, to the endoscopy. Data were collected on whether and which explanatory pathology was found in the endoscopic evaluation. Results: In total, 464 patients were included, of whom, 174 were using a salicylate and 290 were not. In 41.2% of the patients, explanatory pathology was found, which was not significantly different between the two groups with univariate analysis (p = 0.207). However, the patients in the group of salicylate users were significantly older and more often male. When correcting for these differences in group characteristics during multivariate analysis, the use of salicylates was found to be a negative predictive factor for finding explanatory pathology (p < 0.001; OR 2.307). Conclusion: When determining the chance of finding explanatory pathology during endoscopic evaluation in patients with IDA, the use of salicylates should be taken into account as a negative predictive factor for finding explanatory pathology during endoscopic evaluation.