The majority of available potential scores were developed as mortality indicators and perform less well for predicting critical care usage. Amongst ICU admissions with community-acquired pneumonia in Massachusetts in 1996 to 1997, 10/32 scored CURB-65 1 or 2 (that is, low risk) and 5/32 were classified as PSI (Pneumonia Severity Index) class III (intermediate risk) [40] . Even amongst patients with pneumonia included in the PROWESS study, only 90.5% were PSI class IV or V, and only 70.3% had a CURB-65 score of 3 or above [41] .