Agitated Behavior Scale

The Agitated Behavior Scale (ABS) was designed to assess agitation in patients who had sustained a TBI (Corrigan 1989). According to Levy et al. (2005), despite the availability of the scale, agitation remains unmeasured by most who work with the TBI population. The scale, which began as a 39-item scale, was reduced to 14 items, with each item scored from 1 (absent) to 4 (present to an extreme degree). The scale which was originally tested by nurses, occupational therapists, physiotherapists, and other hospital staff was designed to be used by allied health professionals (Corrigan 1989). The total score, which is considered the best overall measure of the degree of agitation, is calculated by adding the ratings (from one to four) on each of the 14 items. The scale can also be divided into three subscales. The Disinhibition subscale includes items 1, 2, 3, 6, 7, 8, 9, and 10; the Aggression subscale includes items 3, 4, 5 and 14; and the Lability subscale includes items 11, 12, and 13 (Corrigan & Bogner 1994). Individual scores of ≥22 on the ABS indicate high agitation, conversely scores of ≤21 indicate low agitation (Corrigan & Mysiw 1988).

Table: Characteristics of the Agitated Behavior Scale

Advantages. This scale was designed to be used specifically with those who had sustained a TBI (Corrigan 1989). The ABS has also been tested with a group of individuals living in a long term care facility and has demonstrated strong internal consistency and inter-rater reliability (Bogner et al. 1999). Bogner et al. (2001) found that there was a strong relationship between cognition and agitation. Higher scores on the MMSE and the Functional Independence Measure (FIM) cognitive subscales were significantly related to lower scores on the ABS (Bogner et al. 2001; Corrigan & Bogner 1994). Administering the scale requires little time and can be completed in less than 30 minutes. Agitation is considered to be present if the score is >21 (Corrigan & Bogner 1995). The scale is free of cost and readily available at www.tbims.org/combi/abs/abs.pdf.

Limitations. The ABS has yet to be validated throughout a wider range of rehabilitation facilities (Corrigan & Bogner 1995). As well, one of the more significant limitations of the ABI is the risk of over-diagnosing agitation (Corrigan & Mysiw 1988). 

 

Summary-Agitated Behavior Scale

Interpretability: Scores on the ABS are easy to interpret: severely agitated ≥36, moderately agitated 29-35, mildly agitated 22-28, and not agitated<22 (Bogner et al. 2000).

Acceptability: The scale is available free of charge and requires little time for training and administration. 

Feasibility: The ABS requires little time to complete and can be completed by all health professionals working with the patient. 

 

Table: ABS Evaluation Summary

Reliability

Validity

Responsiveness

Rigor

Results

Rigor

Results

Rigor

Results

Floor/ceiling

+++

 

+++(IO)

+++(IC)

++

++

++

++

N/A

NOTE: +++=Excellent; ++=Adequate; +=Poor; N/A=insufficient information; TR=Test re-test; IC=Internal Consistency; IO=Interobserver; Varied (re. floor/ceiling effects; mixed results).