Sharon K. Inouye, MD, MPH; Cyrus M. Kosar, MA; Douglas Tommet, MS, MPH; Eva M. Schmitt, PhD; Margaret R. Puelle, BS; Jane S. Saczynski, PhD; Edward R. Marcantonio, MD, SM (1); Richard N. Jones, ScD (1)
* Drs. Marcantonio and Jones contributed equally as co–senior authors.
Note: The CAM algorithm and instrument are copyrighted to the Hospital Elder Life Program, LLC (www.hospitalelderlifeprogram.org). Instructions and training manual are available at the Web site.
Acknowledgment: The authors thank the patients, families, physicians, and research staff who participated in the SAGES and Project Recovery studies and made this study possible. This work is dedicated to the memory of Joshua Bryan Inouye Helfand and Bradley Yoshio Inouye.
Grant Support: By National Institute on Aging grants P01AG031720 and K07AG041835 (Dr. Inouye), R01AG030618 and K24AG035075 (Dr. Marcantonio), and K01AG033643 (Dr. Saczynski). Dr. Inouye holds the Milton and Shirley F. Levy Family Chair.
Disclosures: None. Forms can be viewed at www.acponline.org/authors/icmje/ConflictOfInterestForms.do?msNum=M13-1927.
Reproducible Research Statement: Study protocol, statistical code, and data set: Available on request from Dr. Inouye (e-mail, AgingBrainCenter@hsl.harvard.edu).
Requests for Single Reprints: Sharon K. Inouye, MD, MPH, Aging Brain Center, Institute for Aging Research, Hebrew SeniorLife, 1200 Centre Street, Boston, MA 02459; e-mail, AgingBrainCenter@hsl.harvard.edu.
Current Author Addresses: Drs. Inouye and Schmitt, Mr. Kosar, and Ms. Puelle: Aging Brain Center, Institute for Aging Research, Hebrew SeniorLife, 1200 Centre Street, Boston, MA 02131.
Mr. Tommet: Butler Hospital, Duncan Building, 700 Butler Drive, Providence, RI 02912.
Dr. Saczynski: University of Massachusetts Medical School, Division of Geriatric Medicine, 377 Plantation Street, Biotech 4, Suite 315, Worcester, MA 01655.
Dr. Marcantonio: Harvard Medical School, Division of General Medicine and Primary Care, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02215.
Dr. Jones: Butler Hospital, 345 Blackstone Boulevard, Providence, RI 02906.
Author Contributions:Conception and design: S.K. Inouye, E.R. Marcantonio, R.N. Jones.
Analysis and interpretation of the data: S.K. Inouye, C.M. Kosar, D. Tommet, E.R. Marcantonio, R.N. Jones.
Drafting of the article: S.K. Inouye.
Critical revision of the article for important intellectual content: S.K. Inouye, C.M. Kosar, E.M. Schmitt, M.R. Puelle, J.S. Saczynski, E.R. Marcantonio, R.N. Jones.
Final approval of the article: S.K. Inouye, C.M. Kosar, E.M. Schmitt, M.R. Puelle, J.S. Saczynski, E.R. Marcantonio, R.N. Jones.
Provision of study materials or patients: S.K. Inouye, E.R. Marcantonio.
Statistical expertise: S.K. Inouye, C.M. Kosar, D. Tommet, E.R. Marcantonio, R.N. Jones.
Obtaining of funding: S.K. Inouye, E.R. Marcantonio.
Administrative, technical, or logistic support: S.K. Inouye, C.M. Kosar, E.M. Schmitt, M.R. Puelle.
Collection and assembly of data: S.K. Inouye, C.M. Kosar, D. Tommet, E.M. Schmitt, E.R. Marcantonio.
Inouye S., Kosar C., Tommet D., Schmitt E., Puelle M., Saczynski J., Marcantonio E., Jones R.; The CAM-S: Development and Validation of a New Scoring System for Delirium Severity in 2 Cohorts. Ann Intern Med. 2014;160:526-533. doi: 10.7326/M13-1927
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Published: Ann Intern Med. 2014;160(8):526-533.
Quantifying the severity of delirium is essential to advancing clinical care by improved understanding of delirium effect, prognosis, pathophysiology, and response to treatment.
To develop and validate a new delirium severity measure (CAM-S) based on the Confusion Assessment Method.
Validation analysis in 2 independent cohorts.
Three academic medical centers.
The first cohort included 300 patients aged 70 years or older scheduled for major surgery. The second included 919 medical patients aged 70 years or older.
A 4-item short form and a 10-item long form were developed. Association of the maximum CAM-S score during hospitalization with hospital and posthospital outcomes related to delirium was evaluated.
Representative results included adjusted mean length of stay, which increased across levels of short-form severity from 6.5 days (95% CI, 6.2 to 6.9 days) to 12.7 days (CI, 11.2 to 14.3 days) (P for trend < 0.001) and across levels of long-form severity from 5.6 days (CI, 5.1 to 6.1 days) to 11.9 days (CI, 10.8 to 12.9 days) (P for trend < 0.001). Representative results for the composite outcome of adjusted relative risk of death or nursing home residence at 90 days increased progressively across levels of short-form severity from 1.0 (referent) to 2.5 (CI, 1.9 to 3.3) (P for trend < 0.001) and across levels of long-form severity from 1.0 (referent) to 2.5 (CI, 1.6 to 3.7) (P for trend < 0.001).
Data on clinical outcomes were measured in an older data set limited to patients aged 70 years or older.
The CAM-S provides a new delirium severity measure with strong psychometric properties and strong associations with important clinical outcomes.
National Institute on Aging.
Paul Regal FRACP FRCP
Senior Lecturer in Geriatric Medicine, University of Newcastle, Australia
May 4, 2014
The CAM-S for Delirium versus New Gold Standard of Rapid High Amplitude Critical Reversible Cognitive Decline
Inouye  extended the 24-year old Confusion Assessment Method  (CAM) from dichotomy to the interval CAM-S. Neither qualifies as a gold standard. I offer 13 reasons for switching from CAM to a genuine gold standard: 1) A mathematician would divide cognitive decline into slow non-reversible cognitive decline (SNRCD / dementia) and rapid reversible CD (five phenotypes by cognitive domain); 2) The logical gold standard for RRCD of attention/executive function/memory (delirium) is rapid high amplitude critical reversible decline (RHACRCD): 25% / 24 hours. This greatly exceeds daily variability. RHACRCD is 2,300 fold faster than Alzheimer disease (4% per year); 3) 126 subjects in my prospective randomized controlled delirium trial (CADIS Clinical Trials.Gov NCT01650896) demonstrated 72% decline in executive function by selective instrumental activities of daily living (SIADL) over 24 hours from onset. Attention by 5-digit span forward (5-DSF) fell 33% and 6-DSF 53% ; 4) Speed and amplitude of recovery is the secondary gold standard distinguishing delirium from dementia. 90% of CADIS patients recovered 5-DSF within 7 days, 77% 6-DSF and 53% Delirium Index  (DI). Mean day to resolution was 1.95 for 5-DSF, 5.56 for 6-DSF and 7.82 for DI; 5) A study of 647 acute geriatric admissions in 2011-2012  showed CAM positivity did not predict survival and only predicted nursing home placement in univariate analysis, contradicting Inouye’s  1995-1998 data. 6) The 1990 CAM-4 and the new CAM-S-4 share weaknesses #6-9 : Acute onset occurs frequently in behavioural and psychological symptoms of dementia (BPSD) and psychosis without cognitive decline as in Parkinson’s disease; 7) Fluctuation can occur for a myriad reasons such as sleep deprivation and diffuse Lewy body dementia; 8) The CAM inattention criteria does not mandate new or worsened inattention – 6-DSF is usually impaired in dementia; 9) Disorganized thinking is routine in dementia and detecting worsening in disorganized thinking is subjective. 10) The long-form CAM and CAM-S-10 share additional weaknesses #10-12: disorientation is common in dementia; 11) memory impairment is common in dementia; 12) altered sleep wake cycle occurs in non-delirious hospital inpatients due to procedures disrupting sleep. 13) Inouye  claims poor outcome with higher CAM-S based solely on 919 admissions in 1995-1998, contrasting with favourable outcomes in my 647 admissions in 2011-2012 . 14) The large number of CAM publications reflects bias and ridicule against new methods such as RHACRCD rather than endorsement of CAM; 15) What IADL instrument appeared in Table 1? References:1. Inouye SK, Kosar CM, Tommet D et al. The CAM-S: development and validation of a new scoring system for delirium severity in 2 cohorts. Ann Intern Med. 2014;160:526-533.2. Inouye SK, van Dyck CH, Alessi CA, Balkin S, Siegal AP, Horwitz RI. Clarifying confusion: The confusion assessment method. A new method for detection of delirium. Ann Intern Med. 1990;113:941-48.3. Regal P. Delirium Reversibility and Instrumental Activities of Daily Living (IADL). Geriatrics and Gerontology International. 2014;14:in press4. McCusker J, Cole M, Bellavance F, et al. The reliability and validity of a new measure of severity of delirium. International Psychogeriatrics. 1998;10:421-433.5. Regal P. Confusion Assessment Method (CAM) indicators when CAM positivity in 647 patients has good outcome. J Am Ger Soc. 2013;61:173.6. Regal P. Improving the logic and rigor of delirium trials. Internal Medicine Journal. 2013;43:1260.
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Hospital Medicine, Neurology, Delirium.
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