Inquiry into the diagnostic workup of patients with fever of unknown origin

Background: The utility of algorithms in patients with fever of unknown origin (EUO) has not yet been determined. Before starting a prospective study on the utility of a staged diagnostic protocol in patients with FUO, we performed an inquiry among internists in each university hospital in the Netherlands to obtain insight into their diagnostic approaches to FUO. Methods: Nineteen of 24 internists filled out a questionnaire. The first part consisted of a description of a patient with FUO having few potentially diagnostic clues and questions on the work-up of this patient with FUO. In the second part a multiple-choice form had to be filled out specifying the clinical situations in which one would order in general each of the 182 investigations mentioned. Results: Regarding the first part, a median of 6 (2-16) possible diagnoses was mentioned. Many investigations would be ordered on the basis of this differential diagnosis. Regarding the second part, 38 investigations were ordered as a screening procedure by more than 50% of these internists. A median of 49 investigations was ordered as a screening procedure per internist and 103 investigations on suspicion of a possible diagnosis only. Conclusions: Many investigations were used as screening procedures in the diagnostic process of patients with FUO. A two-staged diagnostic protocol was developed based on retrospective analysis of diagnostic management and data from this study. The diagnostic utility of this protocol will be tested in a large prospective multicentre study.