Hospitalizations for asthma in an urban population: 1995-1999

Asthma hospitalizations occur commonly. Many are preventable if asthma is well controlled. Medications and demographic factors affect asthma hospitalization rates. Recent studies suggest that inhaled long-acting beta-agonists (LABAs) may heighten risk of serious asthma exacerbation, particularly in African Americans.

To further our understanding of the greater asthma morbidity associated with African American race and to investigate possible risk associated with LABAs.

In an ecologic analysis, asthma hospitalization rates in individuals aged 5 to 64 years were determined for Philadelphia zip codes in period 1 (1995-1997) and period 2 (1997-1999) and were studied for associations with asthma drug prescription rates, demographic factors, and numbers and types of asthma care providers.

Higher hospitalization rates were found in African Americans vs Caucasians (45.7 vs 7.6 per 10,000) and in 5- to 17-year-olds vs 18- to 34- and 35- to 64-year-olds (30.4 vs 11.9 and 13.7 per 10,000). Hospitalizations were correlated directly with prescriptions for inhaled short-acting beta-agonists (SABAs) in periods 1 (r(s) = 0.61) and 2 (r(s) = 0.60) and inversely with LABA prescriptions in periods 1 (r(s) = -0.56) and 2 (r(s) = -0.66). Higher SABA prescription rates were also correlated with greater proportions of African Americans per zip code in periods 1 (r(s) = 0.58) and 2 (r(s) = 0.53). At all poverty levels, African Americans had higher hospitalization rates than Caucasians. Asthma hospitalization was significantly associated with poverty area residence (relative risk [RR], 2.29) and with African American race (RR, 4.31) and age (RR, 1.15) as individual-level variables (P < .001, Poisson regression).

These data do not support the contention that LABA exposure is a major cause of asthma morbidity. Risk of asthma hospitalization is strongly associated with being African American.