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Rehab Measures: Agitated Behavior Scale

Link to instrument

Agitated Behavior Scale available here (other languages below) 

Title of Assessment

Agitated Behavior Scale 



Instrument Reviewer(s)

Initially reviewed by Karen McCulloch, PT, PhD, NCS and the TBI EDGE task force of the Neurology Section of the APTA 6/2012

Summary Date



The ABS measures behavioral aspects of agitation during the acute phase of recovery from acquired brain injury including aspects of aggression, disinhibition and lability.


  • 14 item instrument
  • Minimum score is 14, maximum score is 56
  • Each item is rated on a scale from 1 to 4
    • 1=behavior is not present
    • 2=behavior is present to slight degree
    • 3=behavior is present to moderate degree
    • 4=behavior is present to an extreme degree.
  • Subscale scores for disinhibition, aggression and lability can be calculated, in addition to a total score
  • More detailed guidance for test administration can be found at

Area of Assessment


Body Part


ICF Domain




Assessment Type


Length of Test


Time to Administer

Reliable and valid ratings have been demonstrated with 30 minute therapist observations and nursing 8 hour shifts. Ratings based on 10 minute observations are reliable, but different from those based on longer observations, due to the variable nature of agitation.

Number of Items


Equipment Required

No equipment is required.

Training Required

Description of test administration and scoring is provided on the COMBI website.  Training of therapists was conducted by trial use of the instrument with trainees sharing observations and receiving feedback. Specific written descriptions of ratings are available from the test developers, Drs. Corrigan and Bogner at Ohio State University.

Type of training required

Reading an Article/Manual 



Actual Cost

No cost

Age Range


Administration Mode



Acquired Brain Injury; Traumatic Brain Injury 

Populations Tested

  • Traumatic Brain Injury
  • Non-traumatic Brain Injury (encephalopathy, aneurysm rupture, hemmorrhage)
  • Progressive dementia

Standard Error of Measurement (SEM)

Not Established

Minimal Detectable Change (MDC)

Not Established

Minimally Clinically Important Difference (MCID)

Not Established

Cut-Off Scores

Traumatic Brain Injury: (Bogner et al, 2001; n=340 consecutive admissions to TBI unit; mean age=33 years)

  • For total or converted subscale scores:
    • Scores of 21 or below – within normal limits
    • Scores of 22-28 – mild agitation
    • Scores of 29-35 – moderate agitation
    • Scores greater than 35 – severe agitation

Normative Data

Not Established

Test-retest Reliability

TBI: (Corrigan, 1989; n=35; mean age= 28.2; median education= 12 years)

  • Excellent correlation of same day ratings by therapists and nurses (r=.70)

Interrater/Intrarater Reliability

Progressive dementia: (Bogner et al, 1999; n= 23; patients in long term care with progressive demetia)

  • Excellent correlation for total score (r= .906) and factor scores (r=.860 to .886) when rated by research assistants

TBI: (Bogner et al, 1999; n=45; admitted to acute rehab s/p TBI)

  • Excellent correlation for total score (r=.92), with factor correlations for Disinhibition (r=.90), Aggression (r=.91) and Lability (r=.73) when conducted by research assistants
  • Adequate correlations for research staff and nursing ratings (range r=.364 to .604) based on a 10 minute observation from research staff and entire shift ratings by nursing

Internal Consistency

TBI: (Corrigan, 1989; n= 35; mean age= 28.5; currently patients in inpatient rehabilitation)

  • Excellent internal consistency (Chronbach’s alpha values.83-.92)

TBI: (Bogner et al., 1999)

  • Excellent internal consistency (Chronbach’s alpha = .921, .828, nd .801)

Progressive Dementia: (Bogner et al, 1999)

  • Adequate to Excellent internal consistency (Chronbach’s alpha = .74-.808)

TBI, Dementia, and Anoxia: (Bogner et al, 2001; n=152 individuals with acute TBI on rehabilitation unit, n=102 individuals with dementia of Alzheimer’s type; n= 6 with anoxic encephalopathy)

  • Rating scale analysis determined three misfit items: wandering, excessive crying/laughing, and self-abuse. Items among those were observed least often, but not associated with those most agitated.
  • A stable item hierarchy was identified, with a calibration table to allow conversion of ABS scores to interval measures if desired.

Criterion Validity (Predictive/Concurrent)

TBI: (Corrigan, 1989)

  • The ABS score was associated with 36% to 62% of the variance in 15 of 16 correlations with simultaneous, independent observations of agitation by experts

 Predictive validity

TBI: (Bogner et al, 2001; n=340 consecutive admissions to TBI unit; mean age=33 years)

  • Patients designated as having agitation (ABS >21) for more than 48 hours were compared to those who were not agitated
  • Agitation was significantly associated with a longer length of rehabilitation and lower likelihood of being discharged to a private residence
  • Agitation predicted cognitive FIM scores at discharge, but did not predict outcomes at one year (satisfaction with life, productivity)

Construct Validity (Convergent/Discriminant)

Traumatic Brain Injury: (Corrigan & Bogner, 1994; n=212; mean age=31.2 (14.3) years; admissions to inpatient rehabilitation unit with acquired brain injury)

  • Confirmatory factor analysis supported the subscale structure of three components of aggression, disinhibition and lability representing the construct of agitation

Aquired Brain Injury (TBI, aneurysm, brain tumor, anoxia, etc.): (Lequerica et al, 2007; n=69; mean age=42.2 (15.1) years; acute care stay 1-51 days; rehabilitation stay 4-69 days; admissions to TBI rehabilitation unit)

  • Less than 10% of the patients were classified as “agitated” according to a previously described cutpoint of 22 on ABS, yet most patients had some level of behavioral expression of agitation
  • Agitation measured by ABS was significantly correlated (p<.01) with injury severity, engagement in therapy and rehabilitation progress (measured by FIM efficiency ratios)
  • Agitation predicted engagement in therapy to a greater degree (15.3% of variance) than injury severity (10.5%) in a 2-step regression model
  • ABS values much below the suggested cutpoint for agitation may disrupt participation in rehabilitation.

Traumatic Brain Injury and Hypoxia: (Nott et al, 2010; n=8; mean age=34(13) years; median GCS 6; mean time from injury to data collection 37 (17) days)

  • Ratings made over the course of 3 nursing shifts/day over 5 weeks post-injury demonstrated two patterns:
    • Patients beginning at Rancho level V, gradually decreased agitated behaviors over time, especially after emerging from PTA
    • Those patients in PTA with lower cognitive functioning demonstrated higher ABS scores, with higher scores on afternoon shifts, lowest scores at night

Content Validity

Not Established

Face Validity

Acquired Brain Injury: (Corrigan, 1989)

  • Items were selected from an initial 39-item pool based on their testability, differentiation of agitation, frequency of occurrence, and representation of the full domain of the construct

Floor/Ceiling Effects

Not Established


Not Established

Professional Association Recommendations

Recommendations for use of the instrument from the Neurology Section of the American Physical Therapy Association’s Multiple Sclerosis Taskforce (MSEDGE), Parkinson’s Taskforce (PD EDGE), Spinal Cord Injury Taskforce (PD EDGE), Stroke Taskforce (StrokEDGE), Traumatic Brain Injury Taskforce (TBI EDGE), and Vestibular Taskforce (VEDGE) are listed below. These recommendations were developed by a panel of research and clinical experts using a modified Delphi process.


For detailed information about how recommendations were made, please visit:




Highly Recommend




Reasonable to use, but limited study in target group  / Unable to Recommend


Not Recommended



Recommendations based on level of care in which the assessment is taken:


Acute Care

Inpatient Rehabilitation

Skilled Nursing Facility



Home Health








Recommendations for use based on ambulatory status after brain injury:


Completely Independent

Mildly dependant

Moderately Dependant

Severely Dependant







Recommendations for entry-level physical therapy education and use in research:


Students should learn to administer this tool? (Y/N)

Students should be exposed to tool? (Y/N)

Appropriate for use in intervention research studies? (Y/N)

Is additional research warranted for this tool (Y/N)





Not reported


Ratings based on a brief observation may not be capturing the full nature of agitation, since this behavior is known to fluctuate throughout the day. If comparisons are made over time to evaluate a patient’s agitation, it is important that the ratings be done in the same manner each time (based on an entire shift, done at the same time of day, etc).
Translated ABS:
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Amato, S., Resan, M., et al. (2012). "The feasibility, reliability, and clinical utility of the agitated behavior scale in brain-injured rehabilitation patients." Rehabilitation Nursing 37(1): 19-24. Find it on PubMed

Bogner, J. A., Corrigan, J. D., et al. (2000). "Rating scale analysis of the Agitated Behavior Scale." Journal of Head Trauma Rehabilitation 15(1): 656-669. Find it on PubMed

Bogner, J. A., Corrigan, J. D., et al. (2001). "Role of agitation in prediction of outcomes after traumatic brain injury." American Journal of Physical Medicine and Rehabilitation 80(9): 636-644. Find it on PubMed

Bogner, J. A., Corrigan, J. D., et al. (1999). "Reliability of the Agitated Behavior Scale." Journal of Head Trauma Rehabilitation 14(1): 91-96. Find it on PubMed

Corrigan, J. D. (1989). "Development of a scale for assessment of agitation following traumatic brain injury." Journal of Clinical and Experimental Neuropsychology 11(2): 261-277. Find it on PubMed

Corrigan, J. D. and Bogner, J. A. (1994). "Factor structure of the Agitated Behavior Scale." Journal of Clinical and Experimental Neuropsychology 16(3): 386-392. Find it on PubMed

Lequerica, A. H., Rapport, L. J., et al. (2007). "Agitation in acquired brain injury: impact on acute rehabilitation therapies." Journal of Head Trauma Rehabilitation 22(3): 177-183. Find it on PubMed

Nott, M. T., Chapparo, C., et al. (2010). "Patterns of agitated behaviour during acute brain injury rehabilitation." Brain Injury 24(10): 1214-1221. Find it on PubMed

Year published


Instrument in PDF Format

Approval Status Approved 
Created at 11/30/2012 10:03 AM  by Jason Raad 
Last modified at 12/11/2014 10:44 AM  by Jason Raad