Delirium is a common and serious problem, particularly impacting older adults during hospitalization, acute illness, ICU stay, or surgery. Created in 1990 by
Dr. Sharon Inouye, the Confusion Assessment Method (CAM) rapidly became among the most widely used tools for identification of delirium, since it provided a quick, accurate, and standardized approach.
The Confusion Assessment Method (CAM) is a
diagnostic tool
Diagnosis is the identification of the nature and cause of a certain phenomenon. Diagnosis is used in many different disciplines, with variations in the use of logic, analytics, and experience, to determine " cause and effect". In systems engin ...
developed to allow physicians and nurses to identify
delirium
Delirium (also known as acute confusional state) is an organically caused decline from a previous baseline of mental function that develops over a short period of time, typically hours to days. Delirium is a syndrome encompassing disturbances in ...
in the
healthcare
Health care or healthcare is the improvement of health via the prevention, diagnosis, treatment, amelioration or cure of disease, illness, injury, and other physical and mental impairments in people. Health care is delivered by health profe ...
setting.
It was designed to be brief (less than 5 minutes to perform) and based on criteria from the third edition-revision of the
Diagnostic and Statistical Manual of Mental Disorders (DSM-III-R). The CAM rates four diagnostic features, including acute onset and fluctuating course, inattention, disorganized thinking, and
altered level of consciousness
An altered level of consciousness is any measure of arousal other than normal. Level of consciousness (LOC) is a measurement of a person's arousability and responsiveness to stimuli from the environment.
A mildly depressed level of consciousn ...
. The CAM requires that a brief cognitive test is performed before it is completed. It has been translated into more than 20 languages and adapted for use across multiple settings.
Elements of Score
The CAM consists of a short and long form. The CAM short form assesses four features: 1. acute onset or fluctuating course, 2. inattention, 3. disorganized thinking, and 4. altered level of consciousness. The CAM-long form includes the short-form features and adds disorientation, memory impairment, perceptual disturbances, psychomotor agitation or retardation, and altered sleep-walk cycle. These features are based on the 9 features of delirium from DSM-III-R. Each feature is scored as present or absent. Delirium is considered present based on the CAM diagnostic algorithm: presence of (acute onset or fluctuating course -AND‐ inattention) ‐AND EITHER‐ (disorganized thinking or altered level of consciousness) (Table 1). Detailed training and scoring instructions are available here.
Interpretation
In the original study, the 3-5-minute CAM assessment was validated against a >90 minute assessment by reference standard geriatric psychiatrists using DSM-III-R, and found to have a sensitivity and specificity of 94-100% and 90-95%, respectively, for identification of delirium.
In a systematic review of 7 high quality studies involving >1000 patients, CAM was found to have a sensitivity of 94%, 95% CI 91-97%; and specificity of 89%, 95% CI 85-94%.
A 2013 systematic review of 22 studies involving >2400 patients found a sensitivity of 82%, 95% CI 69-91%; and specificity of 99%, 95% CI 87-100%.
A large high-quality STARD-compliant diagnostic
randomized controlled trial
A randomized controlled trial (or randomized control trial; RCT) is a form of scientific experiment used to control factors not under direct experimental control. Examples of RCTs are clinical trials that compare the effects of drugs, surgical te ...
published in 2019 comparing the CAM with the
4AT delirium detection tool found that the CAM had lower sensitivity than the 4AT, with the two tools showing similar specificity. Though some studies show good performance of the CAM in research settings, large scale studies of detection of delirium in real-world clinical practice show that the CAM shows a lower sensitivity (as judged by positive score rates in relation to estimated delirium rates) of around 30-40%.
Adaptations
The table below describes delirium assessment tools based on the CAM, their scoring, and available translations. Additional information (for example: administration and instrument validity) may be foun
here
To Learn More
* https://deliriumnetwork.org/
* https://help.agscocare.org/productAbstract
* https://www.marcusinstituteforaging.org/research/aging-brain-center
References
{{reflist
Mental disorders screening and assessment tools
Intensive care medicine
Geriatric psychiatry