Efficacy of patient questionnaire in predicting renal dysfunction in outpatients older than 60 years of age prior to contrast-enhanced computed tomography

Introduction: Contrast‐induced nephropathy (CIN), a common iatrogenic cause of acute renal failure, is preventable. Identification of impaired renal function prior to intravenous contrast is important. Questionnaire screening has been useful to negate the need for cumbersome and costly renal function testing on all patients prior to contrast‐enhanced CT (CECT). The Royal Australian and New Zealand College of Radiologists guidelines include age older than 60 as a risk marker requiring renal function testing. The aim of this retrospective study is to assess the efficacy of the pre‐CT questionnaire in identifying patients with pre‐existing renal impairment even in this older than 60 age group. Methods: All outpatients were given questionnaires containing 11 CIN risk markers prior to CECT. Radiographers documented age, gender, serum creatinine and/or estimated glomerulofiltration rate (eGFR mL/min/1.72 m2) within 3 months of CT. Questionnaires of all patients older than 60 years were collated. The data was tabulated and analyzed. Incomplete questionnaires were excluded. Results: 134/171 (78.4%) patients had eGFR ≥ 60 and 37/171 (21.6%) had eGFR