International variation in use of imaging for patients presenting with right iliac fossa pain

Aim: To investigate variation in utilisation of diagnostic imaging for patients presenting with right iliac fossa (RIF) pain across five countries. Method: Prospective observational cohort study of adult (16 years and above) patients presenting with RIF pain. The primary endpoint was the overall imaging rate, including computed tomography (CT), magnetic resonance (MRI), and ultrasound imaging. The secondary endpoint was the negative appendicectomy rate (NAR; removal of a histologically normal appendix). Results: Data were collected in Ireland/UK (n¼7665; 169 centres), Italy (n¼782; 50 centres), and Spain/Portugal (n¼1046; 55 centres). Imaging rates were lower in Ireland/UK (women: 74%, men: 41%) than in Italy (women: 87%, men: 84%) and Spain/Portugal (89% for both women and men). Overall CT and MRI scans rates were similar across all countries, but ultrasound was more commonly used in Italy (77%) and Spain/Portugal (81%) than Ireland/UK (46%). The overall NAR was higher in Ireland/UK (16%) than in Italy (3%) and Spain/Portugal (6%). Conclusions: Whilst rates of CT and MRI imaging were similar across the five countries, the NAR was lowest in Italy and Spain/Portugal. It may be possible to decrease the NAR in Ireland/UK without increasing the rate of CT scanning.