DIAGNOSTIC TRAINING IN THE SURVEILLANCE O F NOSOCOMIAL INFECTIONS - WHAT IS FEASIBLE AND USEFUL

The data of surveillance of nosocomial infections are used as clinical indicators of quality. Their diagnosis must therefore be accurate. On e hundred medical records from surgical and intensive care patients we re used to assess the accuracy of diagnosing nosocomial infections acc ording to CDC definitions. All case histories included signs and sympt oms of infection. There were 45 patients with a total of 60 nosocomial infections (18 urinary tract infections, 18 surgical site infections, 11 lower respiratory tract infections and 13 other infection types). After evaluating the medical records, 18 physicians independently deci ded whether or not there was a nosocomial infection and, if so, the ty pe of underlying infection. Their results were compared to the diagnos is of two experienced physicians (gold standard). Twenty-five cases we re assessed on each of four consecutive days and the results were disc ussed with the experienced physicians on the following morning. The di scussions of the first day may thus have been influenced by the result s of the following days. Overall sensitivity was 85.4% (Cl-95 82.8-87. 8%) and overall specificity was 97.1% (Cl-95 95.8-98.0%). Among the mo st common types of nosocomial infections, urinary tract infections had the highest sensitivity (90.1%), followed by surgical site infections (87.3%) and lower respiratory tract infections (85.8%). The specifici ty for these types of infections was 98.2%, 98.9% and 99.5%, respectiv ely. Although the method of investigation used does not fulfill the fo rmal requirements of a validation study for diagnosing nosocomial infe ctions, it seems useful for training in the diagnostics of nosocomial infections or for intermittent evaluation of criteria before starting surveillance activities. This method is useful for training the applic ation of CDC definitions, particularly when the medical records are re duced to case studies that include only the basic information on deter mining the presence of a nosocomial infection in order to evaluate a l arge number of suspected cases in a short period of time.