Delirium is a frequent complication in older ICU patients and often persists beyond their ICU stay. Delirium in older ICU persons is a dynamic and complex process. Dementia is an important predisposing risk factor for the development of delirium in this population during and after the ICU stay.

CAM and CAM-ICU agreement was moderately high. Although the CAM-ICU is recommended for ICU patients because of its brevity and ease of use, the standard CAM method may detect more subtle cases of delirium in nonintubated, verbal ICU patients.

There is a high prevalence of preexisting CI in patients admitted to the medical ICU. Both the MBDRS and IQCODE can be used to screen for preexisting CI in situations where direct patient assessment is not feasible. Future studies are needed to address physician recognition of CI and its effect on patient care decisions and outcomes.

The NH-CAM successfully stratified NH residents' risk of mortality and rehospitalization. If validated clinically, the NH-CAM may be useful in care planning and in further research on the determinants and consequences of delirium in the NH.