Trends in the incidence of noncardiogenic acute respiratory failure: the role of race

Abstract

Objective—We sought to examine trends in the race-specific incidence of acute respiratory failure in the United States. Design—Retrospective cohort study. Setting—We used the National Hospital Discharge Survey (NHDS) database (1992-2007), an annual survey of approximately 500 hospitals weighted to provide national hospitalization estimates. Patients—All incident cases of noncardiogenic acute respiratory failure hospitalized in the United States. Interventions—None Measurements and Main Results—We identified noncardiogenic acute respiratory failure by the presence of ICD–9 codes for respiratory failure or pulmonary edema (518.4, 518.5, 518.81, 518.82) and mechanical ventilation (96.7x), excluding congestive heart failure. Incidence rates were calculated using yearly census estimates standardized to the age and sex distribution of the 2000 census population. Annual cases of noncardiogenic acute respiratory failure increased from 86,755 in 1992 to 323,474 in 2007. Noncardiogenic acute respiratory failure among black Americans increased from 56.4 (95% CI 39.7 – 73.1) to 143.8 (95% CI 123.8 – 163.8) cases per 100,000 in 1992 and 2007, respectively. Among white Americans, the incidence of noncardiogenic acute respiratory failure increased from 31.2 (95% CI 26.2-36.5) to 94.0 (95% CI 86.7 – 101.2) cases per 100,000 in 1992 and 2007, respectively. The average annual incidence of noncardiogenic acute respiratory failure over the entire study period was 95.1 (95% CI 93.9 – 96.4) cases per 100,000 for black Americans compared to 66.5 (95% CI 65.8 – 67.2) cases per 100,000 for white Americans (rate ratio = 1.43, 95% CI 1.42-1.44). Overall in–hospital mortality was greater for other-race Americans, but only among patients with ≥ 2 organ failures (57% [95% CI 56-59%] for other-race, 51% [95% CI, 50-52%] for white, 50% [95% CI, 49-51%] for black). Conclusions—The incidence of noncardiogenic acute respiratory failure in the United States increased between 1992 and 2007. Black and other-race Americans are at greater risk of developing noncardiogenic acute respiratory failure compared to white Americans.