Measuring clinical confusion in critically ill patients

Confusion is frequently undetected by nurses due to superficial patient interviews. This is potentially dangerous for critically ill patients because they may injure themselves and prolong their recovery. Reliable and valid methods of identifying those at risk for developing confusion are needed. As part of a larger study, we tested three measures of confusion in a medical intensive care unit. The Mini-mental State Examination, Clinical Assessment of Confusion-A and Visual Analog Scale of Confusion were administered to 53 critically ill patients for 3-8 days yielding 140 sets of data. Psychometric analyses demonstrated the MMSE, CAC-A and VAS-C were reliable, valid instruments in this population. High correlations were found between instruments, and in over 75% of study days there was agreement in all test scores and clinical assessment of confusion.