Training should provide basic background on the nature of agitation, as well as description of and examples for rating each item. New users should practice rating actual patients, comparing their results to that of experienced users. Written scenarios are available to provide a test standard for assessing competency in administration.
The ABS is an observational as opposed to a self-report measure. Original validation studies showed that nursing staff, physical therapists and occupational therapists can use the scale reliably and validly after receiving appropriate training. At Ohio State University, the ABS is completed by the primary nurse at the end of each shift. Novak and Penrod (1993) report its use at the end of each session by therapy staff.
The ABS has been shown to be reliable and valid when based on therapists' 30-minute observation periods, or primary nurses' perceptions based upon an 8-hour shift (Corrigan, 1989). Ratings based on 10-minute observation periods by psychology assistants or rehabilitation nurses have also been found to be reliable. However, serial monitoring must be done with comparable observations, as it has been found that ratings during 10-minute observation periods are not comparable to ratings based on 8-hour shifts.
Observers rate each of the fourteen items according to a 4-point rating scale. A rating of "1" is ascribed when the behavior in the item is not present. Ratings of "2," "3," and "4" indicate the behavior is present and differentiate the degree or severity. Degree can be a function of either the frequency with which the behavior occurs or the intensity of individual occurrences.
Raters should be instructed that the basis for determining the score is the extent to which the occurrence of the behavior described in the item interferes with functional behavior that would be appropriate to the situation:
• We suggest a rating of "2" or "slight" be ascribed when the behavior is present but does not prevent the conduct of other, contextually appropriate behavior. Patients may redirect themselves spontaneously or the continuation of the agitated behavior does not preclude the conduct of the appropriate behavior.
• A rating of "3" or "moderate" indicates the individual may need to be redirected from an agitated to an appropriate behavior, but is able to benefit from such cueing.
• A rating of "4" or "extreme" is ascribed when the individual is not able to engage in appropriate behavior due to the interference of the agitated behavior, even when external cueing or redirection is provided.
The Total Score is calculated by adding the ratings (from one to four) on each of the fourteen items. Raters are instructed to leave no blanks; but, if a blank is left, the average rating for the other fourteen items should be inserted such that the Total Score reflects the appropriate possible range of values. The Total Score is the best overall measure of the course of agitation (Corrigan, 1989; Corrigan & Bogner, 1994).
Subscale scores are calculated by adding ratings from the component items:
• Disinhibition is the sum of items 1, 2, 3, 6, 7, 8, 9 and 10.
• Aggression is the sum of items 3, 4, 5 and 14. (It is not an error that Item #3 is in both scores.)
• Lability is the sum of items 11, 12 and 13.
In order to allow subscale scores to be compared to each other and to the Total Score, it is recommended that an average item score for each factor be calculated and multiplied by fourteen. This procedure provides subscale scores with the same range as each other and the Total Score, which is useful for graphic presentation (sample graph).
The means and standard deviations for the Total Score and subscale scores are based on samples of persons with traumatic brain injury treated during the acute phases of recovery on an inpatient, rehabilitation unit. A prospective sample of all patients with brain injuries, regardless whether they were demonstrating agitation, revealed an overall mean ABS score of 21.01 and standard deviation of 7.35 for day shift nursing observations (Corrigan, 1989). For clinical purposes, we consider any scores (Total or converted subscale) 21 or below to be within normal limits; from 22 through 28 to indicate mild occurrence; 29 through 35 to indicate moderate; and more than 35 to be severe.
While norms based on a broader sampling of patients from other institutions are desirable, the ABS remains quite usable for ipsative comparisons of the same individual from shift to shift, therapy to therapy, and/or day to day.
Graphical representation of the scores allows for ease in interpretation. Comparisons can be made across time, shift, interventions, factor scores, or other variables. Sample graph
This website has been funded with financial assistance from Grant #H133A120086 awarded by the U.S. Department of Education, National Institute on Disability Rehabilitation Research (NIDRR) to the Ohio Valley Center for Brain Injury Prevention and Rehabilitation for the current funding period of 10/01/2012 - 09/30/2017.