In both locations, discharge rates are highest for female soldiers, with white female subjects having consistently higher rates than black female subjects except during the summer months. On the other hand, black male subjects have higher rates than white male subjects except during the first calendar quarter, although this effect is more pronounced in Europe than in CONUS. Comparative data for the general US population are reported by Evans et al for calendar year 1983 based on the National Hospital Discharge Survey (NHDS). In these data, discharge rates were highest for black subjects in all age and sex groups and for female subjects of all races for those older than 15 yr. Sherman et al reported that female subjects were nearly three times as likely to experience hospitalization as male subjects in a follow-up study of children and adolescents, a finding which may reflect poorer pulmonary function in female asthmatic subjects. further
In all groups, discharge rates among soldiers are lower than comparable civilian figures, in some cases up to a factor of ten. Nevertheless, there is approximate correspondence of risk groups between those identified in the civilian data cited and those reported herein. Differences in respiratory pathogens between the two locations or differences in susceptibility to infection among the defined groups may influence the results observed during winter months. The lack of discrimination of seasonal differences in the NHDS data may also account for some of the observed differences with rates observed among soldiers.Data from the seconed national health and nutrition examination survey (SNHANES) indicate that in the age range examined herein, the prevalence of asthma is greatest in male subjects and black subjects, although the NHDS data reflect the fact that severity, as measured by hospital discharge rates, does not always follow prevalence. The data on soldiers presented herein suggest that seasonal effects are important to consider when comparing demographic groups because average annual relationships may be less representative of disease activity than season-specific rates, due to the marked interseasonal variation in these rates. This is especially true when extrinsic factors are important determinants of the frequency and severity of exacerbations of asthma.