The epidemiology and chronobiology of epistaxis: an investigation of Scottish hospital admissions 1995-2004.

OBJECTIVES: This study aimed at investigating aspects of the epidemiology and chronobiology of emergency admissions with epistaxis in Scotland between 1995 and 2004. In particular, we sought to examine the epidemiology of hospital admission with epistaxis and effects of factors such as day of week, time of year and lunar cycle. DESIGN: A statistical analysis, in terms of descriptive statistics, logistical regression and linear regression, was carried out on data obtained from the Scottish Morbidity Records related to emergency Ear, Nose and Throat (ENT) admissions. SETTING AND PARTICIPANTS: All emergency inpatient admissions for Scottish residents to ENT wards in Scottish NHS hospitals during the 10-year period, between 1st January 1995 and December 31st 2004 were studied. This study only looked at admissions and thus excludes Accident and Emergency attendances caused by epistaxis. MAIN OUTCOME MEASURES: Age, gender, year, month and day of the week of admission were considered, as was relationship to the moon phase. RESULTS: During the study period, the mean daily admission rate with epistaxis was six. Epistaxis accounted for 33% of all ENT emergency admissions. The average age of non-epistaxis ENT emergency admission was 31 years. For epistaxis emergency admissions the median age was 70 years. There were fewer admissions in the summer months [August RR: 0.59 (95% CI: 0.54-0.65) P < 0.001]. There were more admissions at the weekends and on non-weekend public holidays [RR: -0.115 (95% CI -0.160-0.071) P < 0.001]. There was a trend towards a reduction in admission rates from the year 2001. Despite the fluctuations with season and weekday, there was no relationship with phase of the moon [RR: 0.98 (95% CI: 0.88-1.09) for day of the full moon compared with non-full moon weekday]. CONCLUSIONS: This study underlines the importance of epistaxis as the single most frequent emergency diagnosis in ENT. The frequency and patterns of admission show pronounced fluctuations. The observed increase in winter admissions confirms earlier work and may have implications for health resource allocation. Relationships between weekends/public holidays and increased admissions with epistaxis may correspond with social patterns of alcohol use (a known aetiological factor). The lunar cycle does not have an effect on the frequency of epistaxis admissions.