Mortality due to asthma, as well as the prevalence of asthma, have been reported to vary widely throughout the world. Whether this represents true differences and, if so, to what these differences are attributable are issues which are generally problematic due to the multifactorial nature of differences across national boundaries, including differences in ethnicity, environment, and diagnostic and therapeutic practices. The US Army supports large populations of soldiers and their family members in the continental United States (CONUS) and in Central Europe (Europe) and supports much smaller populations in several other regions. Demographically, these populations are quite similar; and, in addition, approximately one third of each population is reassigned to a different population each year, which assures constant and thorough mixing. Health care is provided in army hospitals and health clinics which are staffed largely by military physicians who experience a similar turnover rate. It is the purpose of this report to review observed morbidity and mortality in this demographically homogeneous population receiving identical levels of medical care in different geographic locations in order to determine the quantitative influence of the latter, both on seasonal differences and on secular trends. The contrast will be restricted to CONUS and Europe due to the large proportion of total army strength in these two locations. Here
Materials and Methods
Hospital discharge and mortality summary information were obtained from the individual patient data systems (IPDS) of the patient administration systems and biostatistical activity (PASBA) of the US Army Medical Department for all active-duty soldiers under the age of 35 yr with a primary diagnosis of asthma, as classified by the ninth revision of the ICD (ICD-9, code 493) for the period from January 1984 through December 1988. The age restriction was imposed to avoid the diagnostic uncertainties attending this diagnosis in older groups. Since the bulk of soldiers are in younger groups, the effect of the age restriction was also numerically inconsequential. All discharges were assigned to the area of initial admission in the event of interhospital transfers. In the event that a soldier is admitted to a civilian hospital or dies without admission to a military hospital, the military community to which that soldier belongs notifies the local military hospital which collects summary information on the event and transmits this to PASBA. Denominators for troop strength by calendar quarter were obtained from the Defense Manpower Data Center, Monterey, Calif, by race, age, and sex groups for each geographic location.