GEOGRAPHIC VARIABILITY IN-HOSPITAL ADMISSION RATES FOR RESPIRATORY-DISEASE AMONG THE ELDERLY IN THE UNITED-STATES

Background: The elderly represent a susceptible subpopulation that exp eriences disproportionate levels of morbidity and mortality from respi ratory disease. As a consequence, they are frequently hospitalized for these conditions. Evaluating the geographic distributions of these ho spital admissions can provide useful insights concerning patterns in i ncidence and medical care for respiratory diseases. Methods: All hospi tal admissions for pneumonia, acute respiratory infections, asthma, an d chronic obstructive pulmonary disease from the United States for a 6 -year period (1984 through 1989) were identified using Medicare admiss ions records. Age-, race-, and sex-standardized annual admission rates were calculated for each county and spatial clustering of disease spe cific rates was evaluated using Moran's statistic. Ecologic analyses w ere conducted using multiple regression procedures with county-specifi c measures of average annual temperature, average income, household cr owding, median educational level, population density,physicians per ca pita, and hospital beds per capita together with surrogate measures of cigarette consumption and occupational exposures as predictor variabl es. Results: Hospital admission rates in the elderly for all four cate gories of respiratory disease showed marked regional elevations (p<0.0 001), particularly in the southeast and the northern plains states. Lo w median education level, low per capita income, and household crowdin g were all associated with elevated hospital admission rates. Surrogat e measures of cigarette consumption were strongly associated with hosp ital admissions in all four disease groups. Hospital beds per capita d emonstrated positive associations with hospital admissions, but the nu mber of physicians per capita exhibited consistent inverse relationshi ps with hospital admissions. Conclusions: Hospital admission rates for respiratory diseases among the elderly show marked geographic variati on and are associated with regional indicators of socioeconomic status , availability of medical resources, occupational lung disease rates, and smoking.