2.2. Data collection and processing
Clinical data were obtained from the hospital electronic database. The patients’ demographic characteristics, vital signs at the time of admission to ED, examination findings, chronic diseases, and radiological and laboratory findings were recorded. The CT images evaluated in the study had been acquired using a 128-slice CT device (GE Revolution EVO, USA). The CT findings reported by radiologists were used to evaluate the results. According to the radiologists’ CT reports, the patients were divided into two groups according to whether the source of infection was positive or negative in these reports.
Acute fever of unknown origin was defined as the absence of a history or physical examination finding that could explain the possible cause of fever, absence of non-specific symptoms (such as runny nose, cough, abdominal pain, diarrhea, pain, and burning sensation when urinating), normal values of parameters that would suggest an infection in the urine analysis (bacteriuria, pyuria, and nitrite), and absence of infiltration on chest X-ray. High fever was accepted as a body temperature that was measured as 38.3 °C or higher in ED at least once during treatment (5).