Actual and projected incidence rates for chronic subdural hematomas in United States Veterans Administration and civilian populations

Chronic subdural hematomas (SDHs) are more common among veterans and elderly persons than among members of the general population; however, precise incidence rates are unknown. The purposes of this study were 1) to determine the current incidence of chronic SDH in a US Veterans Administration (VA) population and 2) to create a mathematical model for determining the current and future incidence of chronic SDH as a function of population age, sex, and comorbidity in the United States VA and civilian populations. To determine the actual number of veterans who received a radiographic diagnosis and surgical treatment for SDH during 2000-2012, the authors used the VISN03 VA database. On the basis of this result and data from outside the United States, they then created a mathematical model accounting for age, sex, and alcohol consumption to predict the incidence of SDH in the VA and civilian populations during 2012-2040. Of 875,842 unique (different patient) visits to a VA hospital during the study period, 695 new SDHs were identified on CT images. Of these 695 SDHs, 203 (29%) required surgical drainage. The incidence rate was 79.4 SDHs per 100,000 persons, and the age-standardized rate was 39.1±4.74 SDHs per 100,000 persons. The authors' model predicts that incidence rates of chronic SDH in aging United States VA and civilian populations will reach 121.4 and 17.4 cases per 100,000 persons, respectively, by 2030, at which time, approximately 60,000 cases of chronic SDH will occur each year in the United States. The incidence of chronic SDH is rising; SDH is projected to become the most common cranial neurosurgical condition among adults by the year 2030.