Can a structured questionnaire identify patients with reduced renal function?

Abstract

To evaluate a structured questionnaire in identifying outpatients with renal dysfunction before MRI or CT in various age groups. All patients completed a questionnaire with five risk factors indicating renal dysfunction: renal disease, renal surgery, hypertension, gout and diabetes. Serum creatinine determined by the point-of-care (POC) technique and estimated glomerular filtration (eGFR) rate was calculated using CKD-EPI equation. A total of 1,467 patients were enrolled. Thirty-four patients (2%) had an eGFR <30 ml/min/1.73 m(2) and 123 (8%) had an eGFR <45 ml/min/1.73 m(2). Among 55% of the 1,467 patients reporting at least one risk factor, 30 (4%) had an eGFR <30 ml/min/1.73 m(2) and 105 (13%) had an eGFR <45 ml/min/1.73 m(2). Among 651 patients not reporting a risk factor, 4 (0.6%) had an eGFR <30 ml/min/1.73 m(2) and 18 (3%) had an eGFR <45 ml/min/1.73 m(2). All four patients were >70 years old, and 12 of the 18 patients were >70 years old. The questionnaire used in patients <70 years old and determination of eGFR in patients >70 years old identified all patients with an eGFR between 30 and 45 ml/min/1.73 m(2) except 0.4%. • A questionnaire can adequately identify patients under 70 with renal dysfunction • 8% of patients referred to CT/MRI have an eGFR <45 ml/min/1.73 m (2) • 55% reported risk factors, but renal dysfunction was only found in 13% • Patients over 70 years should have eGFR determined before CT • eGFR determination is not beneficial when stable MRI agents are used.