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ICD Code: 493. Asthma



ICD Code: 493. Article Review
Title: Krishnan V et al; "Mortality in Patients Hospitalized for Asthma Exacerbations in the United States." American Journal of Respiratory and Critical Care Medicine; V.174; 2006; p633
      BURDEN OF SEVERE ASTHMA: In the United States, severe asthma exacerbations lead to over 400,000 hospitalizations each year, and these hospitalizations constitute about one-third of the total $11.5 billion in annual asthma-related health care expenditures.
      STUDY DESIGN: The present authors conducted a study to obtain national estimates of mortality, length of hospital stay, and total hospital charges among patients hospitalized for asthma exacerbations in the United States. They used the Agency for Healthcare Research and Quality-sponsored Nationwide Inpatient Sample (NIS) because it is the largest all-payer source of data on hospitalized patients in the United States. The NIS contains data on all admissions from a 20% stratified probability sample of all acute care nongovernmental hospital admissions in the United States and was designed to provide national estimates of outcomes in this population.
      Admission records were included in this study if the primary discharge diagnosis was (1) asthma (International Classification of Diseases, Ninth Revision, 493.xx) or (2) acute respiratory failure, distress, or arrest (518.81, 518.82, 799.1), with a secondary diagnosis of asthma. Children younger than 5 years were excluded because of the difficulty in establishing asthma in this population. Admission records without data on hospital mortality were also excluded.
      HOSPITALIZATION FOR EXACERBATION: Patients hospitalized for asthma exacerbations were most likely to be white, female, and admitted through the emergency department. The overall hospital mortality for asthma exacerbations was 0.5%. The overall mean hospital length of stay was 2.7 days, and mean hospital charge was $9,078. Patients 5-34 years of age accounted for a minority of asthma deaths (21.4%); most asthma deaths (78.6%) occurred in patients 35 years or older.
      Using the NIS hospital discharge weights, the present analyses indicate that a total of 1499 hospital deaths were due to asthma in the United States for 2000. The authors estimate that asthma exacerbations accounted for 1.1 million hospital days and $2.9 billion in charges. Fewer than 5% of admissions involved intubation/mechanical ventilation. These admissions were associated with a higher risk of death, longer length of hospital stay, and higher hospital charges compared with admissions without intubation/ mechanical ventilation.
      Overall, black and Hispanic patients had a significantly lower risk of hospital mortality compared with white patients.
      DISCUSSION: Although asthma mortality is several-fold higher in blacks compared whites in the overall United States population, black patients hospitalized for asthma exacerbations were not significantly more likely to die than their white counterparts. Even after accounting for other patient and admission characteristics and performing age-stratified analyses, the present authors failed to detect a significantly higher rate of death among black patients hospitalized for asthma exacerbations. These findings suggest that the race disparity in asthma mortality in the United States is attributable to factors that precede hospital admission.
      The authors found 81,900 records for asthma admissions (all ages) in 2000, which represent about 401,000 hospital admissions for asthma based on the NIS hospital discharge weights. Thus, these analyses are based on about 86% of the CDC estimate of 465,000 admissions in 2000, which suggests that the present authors have missed a small proportion of hospitalizations for asthma exacerbations in the United States, particularly admissions to government hospitals (e.g., Veterans Health Administration hospitals), which are not included in the NIS 2000 dataset.

Search Criteria: Text - American Journal of Respiratory and Critical Care Medicine; V.174; 2006; p633