Abstract
This study investigated the frequency of idiopathic epistaxis onset and its severity relative to the time of day. Idiopathic epistaxis was defined as epistaxis in the emergency department, with no epistaxis diagnosis in any hospital 12 months before incident epistaxis. The timing of epistaxis onset was divided into four categories: morning (6:01-12:00), afternoon (12:01-18:00), evening (18:01-24:00), and overnight (00:01-6:00). The chi-square test was used to analyse the time distribution of epistaxis (p ≤ .05).. During the study period, a total of 1684 patients with a median age of 56 years developed epistaxis. Epistaxis incidence was highest in December (n = 213), lowest in July (n = 95), and highest in winter, followed by fall, spring, and summer. Epistaxis occurred most frequently overnight (n = 823, 48.8%), followed by evening (n = 410, 24.3%), morning (n = 254, 15.1%), and afternoon (n = 197, 11.7%; p < .001). Afternoon was selected as the reference. After adjustment for covariates, odds ratios (ORs) and 95% confidence intervals (CIs) of the risk of epistaxis were 1.34 (95% CI, 1.26-1.43), 1.47 (1.38-1.56), and 3.52 (3.14-3.91) in the evening, morning, and overnight, respectively. Epistaxis rates overnight were significantly strongest and positively proportional to blood pressure levels between 0:01 am and 6:00 am (r = 18.1, p < .001), followed by overnight rates (r = 11.5, p = .017). Patients who developed epistaxis overnight were more likely to develop posterior epistaxis and to receive endoscopic electrocoagulation haemostasis (p < .001). In this cohort, these results suggest that adult idiopathic epistaxis occurred most frequently at overnight, especially in the winter, and more need management to immediately control the bleeding in ENT emergency departments. In addition, this study found that high frequent of epistaxis at overnight associated with serious blood pressure between 0:01 am and 6:00 am. This analysis supports that health care professionals and caregiver should be aware of individuals with hypertension, and the status of blood pressure at overnight should be considered in preventing nasal bleeding's risk.