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

Abstract

Object: 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.

Methods: 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.

Results: 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.

Conclusions: The incidence of chronic SDH is rising; SDH is projected to become the most common cranial neurosurgical condition among adults by the year 2030.

Keywords: IEN = internal entry number; LPC = liters per capita; SDH = subdural hematoma; VA = Veterans Administration; atrophy; incidence; mathematical model; subdural hematoma; subdural hemorrhage; trauma; vascular disorders.

Conflict of interest statement

Disclosure The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.

Figures

Fig. 1

Graph showing the incidence rate for chronic SDH (cSDH) in the general US population as a function of time. The y-axis on the left shows the scale for the percentage of the US population older than 65 years. The y-axis on the right shows the scale for incidence rate, shown as number of cases of chronic SDH per 100,000 persons. The upward trend of the blue area in the graph depicts the aging American population. The continuous maroon line depicts the incidence rate for chronic SDH, according to the Japan-based formula, and the interrupted maroon line shows the alcohol-adjusted incidence rate. The continuous orange line depicts the incidence rate according to the Finland-based formula, and the interrupted orange line shows the alcohol-adjusted incidence rate. The graph illustrates the present and projected increase in incidence rates for chronic SDH until 2040 as the population continues to age. Figure is available in color online only.

Fig. 2

Histogram showing the incidence rate for chronic SDH (cSDH) in the VA population as a function of time in years during the study period, 2000–2012. On the y-axis is the scale for incidence rate, shown as number of cases of chronic SDH per 100,000 persons. The blue bars depict the incidence rate for operative chronic SDH cases, and the purple bars depict the incidence rate for nonoperative cases of chronic SDH for that year. The continuous maroon line depicts the estimated incidence rate for chronic SDH in the VA, according to the Japan-based formula when the rate is age weighted to the age distribution of the VA population, and the interrupted maroon line shows the alcohol-adjusted incidence rate. The continuous orange line depicts the incidence rate according to the Finland-based formula when age weighted for the age distribution of the VA population, and the interrupted orange line shows the alcohol-adjusted incidence rate. Figure is available in color online only.