[Minor head injuries in a Copenhagen district. 1. Epidemiology]

The records of 1,218 males and 743 females admitted to Copenhagen County Hospital in Glostrup between January 1 1985 and December 31 1986 were studied. The mean age was 28.2 years (SD = 20.3 years). The incidence rate was 360 per 100,000 inhabitants per year and was between 30 and 130% larger for males than females (p less than 0.001), the incidence rate was 26% higher in this study as compared to the rate in Denmark as a whole. Patients between 0 and 14 years were most frequently admitted between noon and the early evening hours and those between 15 and 64 years most frequently from late in the afternoon until the early night. The distribution was uniform throughout the week. There was a tendency towards more frequent admissions in the April and July trimesters. 74% of the patients were admitted at hours when the staff was minimal. This category comprised 4.9% of all patients admitted as emergencies to the hospital. The mean hospitalization was 1.6 days (range 1-14 days). Females were hospitalized longer than males (p less than 0.001). Furthermore, hospitalization was significantly longer, the older the patients were (p = 0.005). Patients with minor head trauma constitute a considerable work load in the hospital, especially outside normal working-hours.