Underrecognition of preexisting cognitive impairment by physicians in older ICU patients.

OBJECTIVES: Cognitive impairment increases with age, as do many serious illnesses requiring intensive care. Little is known, however, about physician recognition of preexisting cognitive impairment in the ICU and which patient factors may play a role in physician recognition.
DESIGN: Cross-sectional comparative study.
SETTING: Urban university teaching hospital. PARTICIPANTS: A total of 165 patients aged > or =65 years who were admitted to the medical ICU. MEASUREMENTS: Two previously validated proxy measures of cognitive impairment, the modified Blessed dementia rating scale and the informant questionnaire on cognitive decline in the elderly. Physician interviews and medical record abstraction were used to evaluate the recognition of cognitive impairment.
RESULTS: The prevalence of preexisting cognitive impairment in the ICU was 37%. Attending physicians were unaware of the preexisting cognitive impairment in 53% of cases, and intern physicians were unaware in 59% of cases. The recognition of preexisting cognitive impairment increased as the severity of the cognitive impairment increased. Two independent risk factors were identified that were significantly associated with the increased recognition of preexisting cognitive impairment (ie, impairment in activities of daily living or being admitted to the ICU from a nursing home). If both were present, preexisting cognitive impairment was 13 times more likely to be recognized.
CONCLUSIONS: A substantial number of older ICU patients have preexisting cognitive impairment on admission to the ICU, and ICU physicians caring for these patients are unaware of this cognitive impairment in the majority of cases. Future research is needed to identify outcomes related to preexisting cognitive impairment and to improve its recognition.