Background and hypothesisCauses and risk factors for community-acquired acute kidney injury (CA-AKI) have not been thoroughly studied. The aim of this study was to examine the risk factors for CA-AKI. MethodsIn this prospective study, we examined serum creatinine from all individuals visiting a university hospital's emergency department (ED) over an 11-month period for the presence of AKI defined according to the KDIGO criteria. Patients with AKI were invited to participate. Randomly selected controls (1:2) were paired according to age, sex, and date of admission. Participants answered questions about their medical history and medication use, including over-the-counter (OTC) drugs. Conditional logistic regression was used to identify factors associated with AKI. ResultsOf 602 AKI cases identified, 512 participated in the study. AKI cases were significantly more likely than controls to have used nonsteroidal anti-inflammatory drugs (NSAIDs) (26.0 % vs 18.0 %, p = 0,001) in the week preceding the ED visit, particularly OTC NSAIDs (23.3 % vs 15.9 %, p < 0.001). AKI was associated with a recent history of vomiting (OR 2.52 [95 %CI 1.87–3.39]), diarrhea (1.30 [1.00–1.70]) and urinary retention (1.92 [1.36–2.72]), use of non-selective NSAIDs (1.84, [1.37–2.48]), RAAS blockers (1.63 [1.21–2.19]), and diuretics (1.53 [1.13–2.08]), and a history of diabetes (1.42 [1.04–1.94]), CKD (1.36 [1.01–1.83]) and smoking (1.72 [1.24–2.37]). ConclusionsEvents in the setting of acute illness and medication use, including OTC NSAIDs, may play a greater role in the development of CA-AKI than comorbid conditions. Frequent use of OTC NSAIDs is a concern and should be addressed in view of serious adverse effects.