Decline in the mortality rate of stroke has been observed from the 1940s through the early 1980s. Many studies have attributed the decline in mortality to the overall reduction in incidence of stroke accompanied by diminutive changes in case fatality for acute stroke. The objective of this study was to assess trends in hospital discharge rates for cerebrovascular disease in the United States from 1970 to 1983. Data were derived from the National Hospital Discharge Survey, which comprises data on patients discharged from noninstitutional, nonfederal hospitals located in the 50 states and the District of Columbia.

Race was not recorded for approximately 13% of all discharges. For the 1981 discharge records in which race was missing, race was assigned using both the distribution of race in the geographical area of the hospital and the information on diagnosis and expected source of payment. However, this assignment of race was not continued in 1982 and 1983 due to technical difficulties. The author explicitly cautions about deriving conclusions from data by race because of the large percentage of discharge cases with missing race. Most of the analysis was limited to patients aged 45 years or over. The diagnosis of cerebrovascular disease considered ICD codes 430-438 and only the first listed diagnosis on the discharge record was used. In addition, all discharges having cerebral arteriography (ICD 9 CM 88.41) and neck vessel endarterectomy (ICD 9 CM 38.12) were examined for 1979-1983.

In 1981, the age-adjusted hospital rate of cerebrovascular disease for persons 35-74 years of age was 483 per 100,000 for white and 652 per 100, 000 per blacks. Thus, the rate for blacks was 35% higher than the rate for whites. In 1981, for persons over 75 years, the age adjusted rate for blacks was only 3% higher than the corresponding rate for whites. Case fatality at ages 45-64 for black men was over twice the rate for white men and 60% higher for black women compared with white women. However, for ages over 65 years, the racial differential narrowed and the gender differential was reversed. The black excess fatality was now 15% for men and 27% for women. Furthermore, the age-adjusted rate of cerebral angiography was equivalent in blacks and whites aged 35 to 74, while the rate of endarterectomy for blacks was 60% lower than the rate for whites.

The study determined that the discharge rate for cerebrovascular disease was higher for blacks than for whites. However, the rates for two surgical interventions for stroke – cerebral angiography and endarterectomy – were inconsistent with the patterns observed for morbidity and mortality. The rate of cerebral angiography was similar among blacks and whites and the rate of endarterectomy was much lower in blacks than in whites. Furthermore, the author stated that the observed black to white hospitalization rates for cerebrovascular disease were lower than what would be expected from mortality ratios (Soltero, 1978). However, literature shows that blacks tend to use health care services less frequently than whites. Thus, findings based upon discharge rates may underestimate the rate of cerebrovascular disease in blacks since they only include blacks who are hospitalized. Also, blacks with mild strokes may more often go undiagnosed or be treated at home or in institutions than whites with mild strokes.

The introduction of computerized axial tomography in the late 1970s facilitated the detection of strokes, particularly mild strokes or small infarcts. However, blacks may have had less access to the procedure in the early 1980s than whites. Reports have proposed that the low rates of carotid endarterctomy among blacks may be the result of the predominance of intracranial occlusion in blacks (Gross et al 1984, JAMA 1984, Gorelick et al 1984). But, population-based studies of vascular pathology of stroke among the races are needed to verify this supposition. The author states that caution must be used in interpreting the race-specific data due to the large percentage of discharge cases with race imputed. Nevertheless, controlling for the 13% of the discharge cases in which race was imputed, the morbidity and mortality rate for cerebrovascular disease would still remain higher among blacks and whites. Analogously, the rate of endarterectomy for blacks would still be much lower among blacks than whites. Thus, in 1982 racial differential in mortality and morbidity for cerebrovascular disease and its therapeutic intervention existed.

Furthermore, the data suggest that a racial differential in diagnosis of cerebrovascular disease may have existed. The author succinctly states that “studies should also be done to determine whether blacks have access to diagnostic and therapeutic facilities for cerebrovascular disease appropriate for their high incidence and mortality.”