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  • Measure Summary
  • NQMC:000231
  • Dec 1990

Delirium: proportion of patients meeting diagnostic criteria on the Confusion Assessment Method (CAM).

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 Dec 15;113(12):941-8. PubMed External Web Site Policy

View the original measure documentation External Web Site Policy

This is the current release of this measure.

The measure developer reaffirmed the currency of this measure in April 2016.

Primary Measure Domain

Clinical Quality Measures: Outcome

Secondary Measure Domain

Clinical Quality Measure: Process

Description

This measure assesses the proportion of patients meeting the diagnostic criteria for delirium as measured by the Confusion Assessment Method (CAM) instrument.

Rationale

Delirium is a common, serious, and potentially preventable source of morbidity and mortality for older hospitalized patients. Delirium has assumed particular importance because patients over 65 currently account for more than 48% of all days of hospital care. Between 14 and 56% of older hospitalized persons suffer from delirium, which means that roughly 2.4 million hospitalized individuals (representing 17.5 million hospital days) are affected by delirium each year in the United States. Delirium often initiates a cascade of events that culminate in functional decline, increased caregiver burden, and increased morbidity and mortality. For example, a meta-analysis found that older patients with delirium had longer hospital stays, higher mortality rates, and higher rates of institutional care than did an unmatched control group. Expenditures for delirium have been estimated at between $16,303 to $64,421 per patient, which translates to $164 billion per year (in 2011 U.S. dollars).

Substantial additional costs accrue following hospital discharge because of the increased need for institutionalization, rehabilitation, and home care. Importantly, the incidence of delirium is likely to increase with the aging of the population. These projections highlight the clinical and health policy implications of delirium. Moreover, delirium meets the criteria for a health care quality indicator: it is common, frequently iatrogenic, and integrally linked to processes of care. Thus, delirium fulfills Williamson's principle of "maximal achievable benefit: the diagnosis is frequent, deficiencies in care are common and serious, and the deficiencies are correctable." Inouye SK, et al. (1999) highlights the important implications of delirium as a marker of quality of health care for older persons. Because of its ease of use, the Confusion Assessment Method (CAM) is currently the most widely used instrument for detection of delirium worldwide. The CAM instrument has been used in over 5,000 original articles to date and has been translated into over 20 languages (Sacynski et al., 2014; Schuurmans et al., 2003; Shi et al., 2013; van Velthuijsen et al., 2016).

Evidence for Rationale

Inouye SK, Schlesinger MJ, Lydon TJ. Delirium: a symptom of how hospital care is failing older persons and a window to improve quality of hospital care. Am J Med. 1999 May;106(5):565-73. [103 references] PubMed External Web Site Policy

Inouye SK, Westendorp RG, Saczynski JS. Delirium in elderly people. Lancet. 2014 Mar 8;383(9920):911-22. PubMed External Web Site Policy

Inouye SK. The Confusion Assessment Method (CAM) for detection of delirium. National Quality Measures Clearinghouse (NQMC) submission [unpublished]. 1990 Dec 15. 1 p.

Leslie DL, Marcantonio ER, Zhang Y, Leo-Summers L, Inouye SK. One-year health care costs associated with delirium in the elderly population. Arch Intern Med. 2008 Jan 14;168(1):27-32. PubMed External Web Site Policy

Leslie DL, Zhang Y, Bogardus ST, Holford TR, Leo-Summers LS, Inouye SK. Consequences of preventing delirium in hospitalized older adults on nursing home costs. J Am Geriatr Soc. 2005 Mar;53(3):405-9. PubMed External Web Site Policy

Rubin FH, Neal K, Fenlon K, Hassan S, Inouye SK. Sustainability and scalability of the hospital elder life program at a community hospital. J Am Geriatr Soc. 2011 Feb;59(2):359-65.

Saczynski JS, Kosar CM, Xu G, Puelle MR, Schmitt E, Jones RN, Marcantonio ER, Wong B, Isaza I, Inouye SK. A tale of two methods: chart and interview methods for identifying delirium. J Am Geriatr Soc. 2014 Mar;62(3):518-24. PubMed External Web Site Policy

Schuurmans MJ, Deschamps PI, Markham SW, Shortridge-Baggett LM, Duursma SA. The measurement of delirium: review of scales. Res Theory Nurs Pract. 2003 Fall;17(3):207-24. [40 references] PubMed External Web Site Policy

Shi Q, Warren L, Saposnik G, Macdermid JC. Confusion assessment method: a systematic review and meta-analysis of diagnostic accuracy. Neuropsychiatr Dis Treat. 2013;9:1359-70. PubMed External Web Site Policy

van Velthuijsen EL, Zwakhalen SM, Warnier RM, Mulder WJ, Verhey FR, Kempen GI. Psychometric properties and feasibility of instruments for the detection of delirium in older hospitalized patients: a systematic review. Int J Geriatr Psychiatry. 2016 Feb 21; PubMed External Web Site Policy

Wei LA, Fearing MA, Sternberg EJ, Inouye SK. The Confusion Assessment Method: a systematic review of current usage. J Am Geriatr Soc. 2008 May;56(5):823-30.

Williamson JW. Formulating priorities for quality assurance activity. Description of a method and its application. JAMA. 1978 Feb 13;239(7):631-7. PubMed External Web Site Policy

Zaubler TS, Murphy K, Rizzuto L, Santos R, Skotzko C, Giordano J, Bustami R, Inouye SK. Quality improvement and cost savings with multicomponent delirium interventions: replication of the Hospital Elder Life Program in a community hospital. Psychosomatics. 2013 May-Jun;54(3):219-26. PubMed External Web Site Policy

Primary Health Components

Delirium; assessment; diagnosis

Denominator Description

All patients studied, typically a cohort of older persons, such as hospital or nursing home admissions

Numerator Description

The number of patients from the denominator meeting the diagnostic criteria for delirium as assessed by the Confusion Assessment Method (CAM) instrument.

Type of Evidence Supporting the Criterion of Quality for the Measure

  • One or more research studies published in a National Library of Medicine (NLM) indexed, peer-reviewed journal

Additional Information Supporting Need for the Measure

  • Delirium, defined as an acute disruption of attention and cognition, occurs in 14% to 56% of older hospitalized patients and is the most frequent complication of hospitalization in these patients.
  • Delirium, also known as acute confusional state, is a common, serious, and potentially preventable source of morbidity and mortality among hospitalized older patients.
  • The development of delirium in the hospital is associated with mortality rates of 25% to 33%, increased morbidity, functional decline, increased need for nursing surveillance, greater hospital costs, increased length of stay and greater rates of nursing home placement.
  • Based on 1994 figures, each year delirium complicates hospital stays for over 2.3 million older persons, involving over 17.5 million inpatient days, and accounting for over $4 billion of Medicare expenditures. Substantial additional costs accrue following hospital discharge because of the increased need for institutionalization, rehabilitation, and home care.

Evidence for Additional Information Supporting Need for the Measure

American Geriatrics Society Expert Panel on Postoperative Delirium in Older Adults. Postoperative delirium in older adults: best practice statement from the American Geriatrics Society. J Am Coll Surg. 2015 Feb;220(2):136-48.e1. PubMed External Web Site Policy

Inouye SK, Bogardus ST Jr, Charpentier PA, Leo-Summers L, Acampora D, Holford TR, Cooney LM Jr. A multicomponent intervention to prevent delirium in hospitalized older patients. N Engl J Med. 1999 Mar 4;340(9):669-76. PubMed External Web Site Policy

Inouye SK, Kosar CM, Tommet D, Schmitt EM, Puelle MR, Saczynski JS, Marcantonio ER, Jones RN. The CAM-S: development and validation of a new scoring system for delirium severity in 2 cohorts. Ann Intern Med. 2014 Apr 15;160(8):526-33. PubMed External Web Site Policy

Inouye SK, Schlesinger MJ, Lydon TJ. Delirium: a symptom of how hospital care is failing older persons and a window to improve quality of hospital care. Am J Med. 1999 May;106(5):565-73. [103 references] PubMed External Web Site Policy

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 Dec 15;113(12):941-8. PubMed External Web Site Policy

Inouye SK. Enhancing Cognitive Aging: Clinical Highlights of a Report From the Institute of Medicine. Ann Intern Med. 2015 Jun 23; PubMed External Web Site Policy

Marcantonio ER, Ngo LH, OConnor M, Jones RN, Crane PK, Metzger ED, Inouye SK. 3D-CAM: derivation and validation of a 3-minute diagnostic interview for CAM-defined delirium: a cross-sectional diagnostic test study. Ann Intern Med. 2014 Oct 21;161(8):554-61. PubMed External Web Site Policy

O'Mahony R, Murthy L, Akunne A, Young J, for the Guideline Development Group. Synopsis of the National Institute for Health and Clinical Excellence Guideline for Prevention of Delirium. Ann Intern Med. 2011 Jun 7;154(11):746-51. PubMed External Web Site Policy

Steis MR, Evans L, Hirschman KB, Hanlon A, Fick DM, Flanagan N, Inouye SK. Screening for delirium using family caregivers: convergent validity of the Family Confusion Assessment Method and interviewer-rated Confusion Assessment Method. J Am Geriatr Soc. 2012 Nov;60(11):2121-6. PubMed External Web Site Policy

Wei LA, Fearing MA, Sternberg EJ, Inouye SK. The Confusion Assessment Method: a systematic review of current usage. J Am Geriatr Soc. 2008 May;56(5):823-30.

Wong CL, Holroyd-Leduc J, Simel DL, Straus SE. Does this patient have delirium?: value of bedside instruments. JAMA. 2010 Aug 18;304(7):779-86. PubMed External Web Site Policy

Extent of Measure Testing

When validated against the reference standard ratings of geriatric psychiatrists' ratings based on comprehensive psychiatric assessment, the Confusion Assessment Method (CAM) had a sensitivity of 94-100%, specificity of 90-95%, positive predictive value of 91-94%, and a negative predictive value of 90-100%. The interobserver reliability of the CAM was high (Kappa = 0.81-1.0). Since delirium is a fluctuating condition by nature, test-retest reliability cannot be validly assessed.

Evidence for Extent of Measure Testing

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 Dec 15;113(12):941-8. PubMed External Web Site Policy

Wei LA, Fearing MA, Sternberg EJ, Inouye SK. The Confusion Assessment Method: a systematic review of current usage. J Am Geriatr Soc. 2008 May;56(5):823-30.

State of Use

Current routine use

Current Use

Internal quality improvement

Measurement Setting

Assisted Living Facilities

Hospital Inpatient

Hospital Outpatient

Skilled Nursing Facilities/Nursing Homes

Professionals Involved in Delivery of Health Services

Nurses

Physicians

Psychologists/Non-physician Behavioral Health Clinicians

Least Aggregated Level of Services Delivery Addressed

Single Health Care Delivery or Public Health Organizations

Statement of Acceptable Minimum Sample Size

Unspecified

Target Population Age

Age greater than or equal to 65 years

Target Population Gender

Either male or female

National Quality Strategy Aim

Better Care

National Quality Strategy Priority

Prevention and Treatment of Leading Causes of Mortality

IOM Care Need

Getting Better

IOM Domain

Effectiveness

Case Finding Period

Unspecified

Denominator Sampling Frame

Patients associated with provider

Denominator (Index) Event or Characteristic

Institutionalization

Denominator Time Window

Does not apply to this measure

Denominator Inclusions/Exclusions

Inclusions
All patients studied, typically a cohort of older persons, such as hospital or nursing home admissions

Exclusions
Unspecified

Exclusions/Exceptions

Unspecified

Numerator Inclusions/Exclusions

Inclusions
The number of patients from the denominator meeting the diagnostic criteria* for delirium as assessed by the Confusion Assessment Method (CAM) instrument

*The measure is scored based on ratings of four key features of delirium:

  1. Acute onset and fluctuating course
  2. Inattention
  3. Disorganized thinking
  4. Altered level of consciousness

The diagnosis of delirium by CAM requires the presence of features (1), (2), and either (3 or 4).

Exclusions
Unspecified

Numerator Search Strategy

Institutionalization

Data Source

Paper medical record

Type of Health State

Clinically Diagnosed Condition

Instruments Used and/or Associated with the Measure

Confusion Assessment Method (CAM)

Measure Specifies Disaggregation

Does not apply to this measure

Scoring

Rate/Proportion

Interpretation of Score

Desired value is a lower score

Allowance for Patient or Population Factors

Unspecified

Standard of Comparison

Internal time comparison

Original Title

The Confusion Assessment Method (CAM) for detection of delirium.

Submitter

Inouye, Sharon K., MD, MPH - Independent Author(s)

Developer

Inouye, Sharon K., MD, MPH - Independent Author(s)

Funding Source(s)

None

Composition of the Group that Developed the Measure

Sharon K. Inouye, MD, MPH, Professor of Medicine, Harvard Medical School

Financial Disclosures/Other Potential Conflicts of Interest

None

Adaptation

This measure was not adapted from another source.

Date of Most Current Version in NQMC

1990 Dec

Measure Maintenance

Unspecified

Date of Next Anticipated Revision

Unspecified

Measure Status

This is the current release of this measure.

The measure developer reaffirmed the currency of this measure in April 2016.

Source(s)

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 Dec 15;113(12):941-8. PubMed External Web Site Policy

Measure Availability

Source available from The Hospital Elder Life Program (HELP) Web site External Web Site Policy.

For more information, contact HELP at the Aging Brain Center, Institute for Aging Research at 1200 Centre Street, Boston, MA 02131; Phone: 617-971-5390; E-mail: elderlife@hsl.harvard.edu; Web site: www.hospitalelderlifeprogram.org External Web Site Policy.

NQMC Status

This NQMC summary was completed by ECRI on February 27, 2003. The information was verified by the measure developer on March 3, 2003.

This NQMC summary was retrofitted into the new template on May 19, 2011.

The information was reaffirmed by the measure developer on April 20, 2016.

Copyright Statement

This NQMC summary is based on the original measure, which is subject to the measure developer's copyright restrictions.

The Confusion Assessment Method (CAM) is copyrighted by the Hospital Elder Life Program, LLC. Anyone wishing to replicate the CAM in printed or electronic form should visit http://www.hospitalelderlifeprogram.org External Web Site Policy and e-mail AgingBrainCenter@hsl.harvard.edu for further information.

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