Appropriateness: analysis of outpatient radiology requests.

Purpose: This study assessed radiology requests and the influence of previous radiological procedures on their specificity and appropriateness, evaluated diagnostic outcomes and recorded the economic impact of inappropriate examinations.
Materials and Methods: We prospectively analysed 4,018 outpatient requests, the appropriateness of which was assessed using an evaluation form. Economic analysis was based on costs listed in the Italian National Health Services (NHS) national tariff as established by the Ministerial Decree of 22 July 1996. Statistical analysis was carried out using Pearson's test and univariate and multivariate logistic regression models.
Results: Of 4,018 outpatient requests, 57% were not included in a follow-up protocol and 56% were found to be appropriate. The diagnostic question was confirmed in 66% of cases considered appropriate (p<0.001). The existence of previous investigations had a significant impact on appropriateness and diagnostic outcome (p<0.001). The total cost of the requests was 257,317 euro, with inappropriate requests accounting for 94,012 euro (36.5%).
Conclusions: We found a 56% rate of appropriate requests and demonstrated that appropriate prescriptions provided with a specific clinical question led to significantly higher confirmation rates of the diagnostic hypothesis. In addition, inappropriate requests had a major negative economic impact.