2.1. Patient selection
This study retrospectively reviewed the records of patients who presented to the ED of our hospital with the complaint of high fever between January 1, 2020 and December 31, 2020. The case presentations were classified using the International Classification of Disease-10 coding system. Accordingly, the patients diagnosed with the R50-50.9 codes in this system (fever with chills, fever of other and unknown origin, persistent fever, and unspecified fever) were screened, and of these patients, those aged 18 and over who underwent thorax and abdomen CT imaging as a diagnostic test were included in the sample. Patients with incomplete records, cases in which CT findings were not reported by a radiologist, those with a history of trauma, those who used empirical antibiotics, and those under the age of 18 years were excluded from the study. Local ethics committee approval was obtained for the study (ethics committee number: 2021/01-79).