Unique characteristics of frequent presenters to the emergency department in a Japanese population: a retrospective analysis.

Aim Little evidence on Japanese frequent presenters (FPs) is available. Therefore, this retrospective cohort study compared characteristics between FPs and non-frequent presenters (NFPs) in emergency departments (EDs) in Japan. Methods Frequent presenters included those who presented to an ED >= 4 times during the study period from August 1, 2012 to July 21, 2013. The primary outcomes were triage level and disposition. Secondary outcomes were ED length of stay, method of arrival, and discharge diagnosis. Results During the study period, 195 FPs had 1,154 visits to the ED, compared to 15,953 visits by 13,838 NFPs. The sex distribution between FPs and NFPs was comparable (107 men [54.9%] versus 7,070 men [51.1%], respectively; P = 0.29), but the mean age was significantly higher in the FP group (57.3 versus 46.5 years, respectively; P < 0.0001). Among the FPs, the rate of free governmental health insurance was higher than that of those who pay 30% of health costs (35 patients paid 0% [79.5%] versus 109 patients paid 30% [42.6%], respectively). Condition severity (FP, 84 severe cases [7.28%]; NFP, 1,320 severe cases [8.27%], respectively) and rate of admission (FP, 207 admissions [17.9%]; NFP, 2,987 admissions [18.7%], respectively) were comparable between the groups, although the rate of ambulance use was lower for the FP group. The most frequent diagnostic codes (International Classification of Diseases, 10th Revision) in the FP group were "symptoms and signs". Conclusion Triage levels and hospital admission rates were not significantly different between FPs and NFPs in this single-center study in Japan.