Because of the warmer climate, persons in Los Angeles may spend less time indoors, where dust mites, molds, and other triggers of asthma reside, as compared with east coast residents. Conversely, Los Angeles residents are exposed to higher concentrations of major air pollutants than residents of east coast cities. In the Los Angeles consolidated metropolitan statistical area, the national ambient air quality standards for carbon monoxide and ozone were not achieved for a total of 20 and 98 days, respectively, in 1993; by comparison, these standards were not met in the New York-New Jersey-Connecticut consolidated metropolitan statistical area during a total of zero and 6 days, respectively, in 1993. However, the association between asthma morbidity and mortality and outdoor air quality remains speculative. Lang and Polansky recently reported increasing rates of asthma mortality in Philadelphia between 1965 to 1990 despite declines in the concentrations of major air pollutants. canadian neighborhood pharmacy
There are several noteworthy study limitations. First, the California Hospital Discharge data source used in this study did not permit an assessment of the prevalence of asthma in California because it is limited to hospital discharges only. Thus, it is unknown whether the lower rates of hospitalization among whites and Asians are due to a lower prevalence of asthma or simply fewer asthma-related hospitalizations. Furthermore, it is not possible to determine whether observed differences in rates among specific cohorts were due to higher numbers of individuals being hospitalized or a higher rate of readmission among some subgroups. Second, there are inherent problems of disease classification when employing secondary data sources. In the California Hospital Discharge file, the disease-specific estimates of inpatient health-care utilization are based on diagnostic information coded via ICD-9-CM diagnosis codes. The specific conditions and the sequence of how these conditions are reported on medical face sheets depend on the interpretation by medical personnel and may therefore not be consistent. Cunningham et al found that black race was an important risk factor for diagnosed asthma but not for persistent wheeze, suggesting that race plays a role in the diagnosis of asthma.