Richard E Pow, Claudia Mello-Thoms, Patrick Brennan

Diagnostic error in radiology is not uncommon, with rates of clinically significant error reported to be as high as 20%. Radiological errors are often multifactorial, however, perceptual factors are thought to be mainly responsible. One way of reducing perceptual error is that of double reporting, which refers to the interpretation of radiological investigations by two observers, with strategies of arbitration and consensus available to settle discordant reports. Independent double reporting, where observers have no knowledge of each other's reports, is generally considered to be the most effective form. The impact of double reporting on diagnostic efficacy has been primarily explored in screening mammography, where it has consistently been shown to improve sensitivity, cancer detection rate and depending on local policy, have a positive influence on recall rates. Subsequently, the adoption of double reporting is reported as standard practice in many national and regional breast cancer-screening programmes. To a lesser extent, the impact of double reporting has also been investigated for neuroradiology, thoracic and gastrointestinal imaging, with small-scale studies in these fields showing promising results. With the widespread implementation of digitisation and the ease of access to images, the efficacy and cost-effectiveness of double reporting for other common radiological investigations requires attention. The review will evaluate the evidence regarding the effect of double interpretation of diagnostic imaging studies on test accuracy.