Impact of contact isolation in the emergency department: a retrospective cohort study

Background : Contact isolation in emergency departments is applied to prevent transmission of pathogens to exposed and predisposed people. However, investigations of the time-bound effects of isolation measures in emergency departments, including evidence on the effects of the overall length of stay in isolated patients, are scarce. Objective : To investigate the effects of contact isolation in an emergency department on the door-to-doctor-time and on door-to-door-time. Methods : Observational retrospective cohort data analysis. Data of a university hospital in Oldenburg, Germany, provided by the German AKTIN register (alliance for information and communication technology in intensive care and emergency medicine), from the period from 1 July 2021 to 31 December 2023, with a total of 80,534 patients (4% in contact isolation). The primary outcome were door-to-doctor-time and emergency department length of stay, depending on the triage group. Secondary outcomes were the frequencies of admissions to an IMC/intensive care unit or normal ward and of fulfilling the sepsis criteria (qSOFA). Main Results : Comparing isolated to non-isolated patients, there was a significant difference in triage groups 2, 3 and 4, the median time spent waiting for a doctor was 4 (group 2), 3 (group 3) and 7 (group 4) minutes longer in isolated patients. An impressive difference was a longer length of stay in the emergency department of isolated patients, the median difference was 151 minutes (group 1), 83 minutes (group 2), 123.5 minutes (group 3), 165.5 minutes (group 4) and 7 minutes (group 5, no significance). Isolated patients were more likely to have a positive qSOFA score (4.1% vs 1.7%) and to be admitted (49% vs 28.6%). They were also older, with a mean of 57.79 years vs. 53.24 years. No difference was found regarding the frequency of admission to an IMC/intensive care unit. Conclusions : In certain triage groups, isolated patients showed a longer emergency department length of stay and waiting period until they were first seen by a doctor. To provide equal medical care, hospitals shall aim to reduce boarding times in isolated patients.