Table 1

Details of how each item on the CAM was scored by the CAM assessors

Example of how the CAM was performed
  1. Introduction: “Hello, Mr…. My name is …. As you have been informed, a study is ongoing in the hospital today and earlier you agreed to participate. You have already answered some questions for us. Are you happy for me to ask you some more questions as part of the same study? It should not take longer than five minutes.”

  2. General assessment: General conversation questions to assess if any obvious distractibility or disorganised thinking (eg, how are you feeling today?; how long have you been in hospital?; etc.)

  3. Formal assessment: Testing of attention and thought process using methods described below.

  4. Nursing questionnaire: Responses from screening nursing questionnaire viewed for information relating to temporal onset and fluctuations

CAM itemHow each item was scored
1A: Acute onsetThis was scored using answers from the standardised nursing interview.
1B: Fluctuating course The raters observed for evidence of fluctuations during the CAM interview. The standardised nursing interview was also used to assess for presence of fluctuations.
2: Inattention The SSF and MOTYB were repeated by the CAM assessors. This item was positive if either one of the tests was failed on this occasion, or if there was evidence of inattention or distractibility during the interview. The results from the initial screening attention tests were not used.
3: Disorganised thinking The patient was asked the following questions:
  •  ▸ Can you tell me what this proverb means? ‘Every cloud has a silver lining’ (example)

  •  ▸ Abstract questions*:

    •  1. Would a stone float on water?

    •  2. Would two pounds of flour weigh more than one pound?

Disorganised thinking was considered present if the patient was unable to correctly interpret the proverb or answered either of the abstract questions incorrectly, or if the patient demonstrated obvious evidence of disorganised thinking during the interview.
4: Altered level of consciousnessThis item was considered positive if there was any evidence of drowsiness/hyperalertness during the interview.
  • *From the CAM-ICU.17

  • CAM, Confusion Assessment Method; MOTYB, Months of the Year backwards; SSF, Spatial Span Forwards.