Incidence of ARDS in an adult population of northeast Ohio

Study objectives: To assess the incidence of the ARDS in a well-defined adult population. Design: Kaiser Permanente of northeast Ohio, a health maintenance organization, uses the Cleveland Clinic Foundation as its only tertiary care center. In an ongoing prospective assessment in the Cleveland Clinic ICUs, we identified adult Kaiser Permanente patients with ARDS between 1996 and 1999. ARDS was defined according to the 1994 American-European Consensus Conference criteria. The denominator in the incidence calculation was the adult members of Kaiser Permanente of each year of the study period, and the numerator was the new adult ARDS patients in this particular year. The cause of ARDS, the mortality, and the cause of death were retrospectively identified, as well as other characteristics of the study population. Results: ARDS was diagnosed in 66 patients during the 3-year study period. The incidence per 100,000 population was 11.4 in 1996, 19.8 in 1997, and 14.4 in 1998; the overall incidence was 15.3/100,000/yr. The mean Paoz/fraction of inspired oxygen (+/- SD) was 110.8 +/- 37.8, the mean APACHE II was 23.4 +/- 6.9, and the mean ICU stay was 12.0 +/- 9.5 days. The most common cause of ARDS was direct lung injury (75.8%), and the most common cause of death was septic shock (53.8%). Conclusion: The incidence of ARDS in an adult population in northeast Ohio was 15.3/ 100,000/yr, a number that is slightly higher but comparable to recent estimates reported by other researchers.