The first citation needed under the epidemiology section comes from: Luhr OR, Antonsen K, Karlsson M. Incidence and mortality after acute respiratory failure and acute respiratory distress syndrome in Sweden, Denmark, and Iceland. The ARF Study Group. Am J Respir Crit Care Med. Jun 1999;159(6):1849-61.
However, the statement above mine is correct and the actual figure is acually around 86.2 in 100,000 person-years from: Rubenfeld GD, Caldwell E, Peabody E, Weaver J, Martin DP, Neff M. Incidence and outcomes of acute lung injury. N Engl J Med. Oct 20 2005;353(16):1685-93.