Agitation Duration, Density and Intensity
during Acute Inpatient Rehabilitation
Predict
Length of Stay in Acute Inpatient Rehabilitation
and
Motor FIMsTM at Discharge
for
Patients with Traumatic Brain Injury
MA Bockbrader, A Nielsen, C Kudron, L Worthen-Chaudhari, J Rosenthal, D
Mortimer, WJ Mysiw, J Bogner, J Corrigan
Objective
 To examine the relationship between Traumatic Brain
Injury (TBI) outcomes and duration, density and
intensity of agitation during inpatient rehabilitation
(IPR).
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Disclosures
 Research supported by NIDRR TBI Model Systems
grant to J Bogner and J Corrigan
 Marcie Bockbrader has nothing to disclose
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AGITATION
 DFN: excessive behaviors occurring during an altered
state of consciousness (Bogner, Corrigan, 1995); for TBI,
the altered state of consciousness is post-traumatic
amnesia (PTA).
 E.g., aggressive, labile, or disinhibited behaviors
 Interferes with functional activity
 Can affect therapy participation
 Hypothesis:
Agitation affects recovery and outcomes after TBI
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Agitated Behavior Scale (Corrigan 1989)
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Items
 Each item rated 1 (none) – 4 (extreme) per 8h shift
 Total score range: 14 – 56
 Cutoff for agitation: total score > 21
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Background
 Bogner et al. 2001
 n= 340 TBI patients in IPR
 Agitation as categorical variable
1. Presence of agitation
Agitated: at least one 48-hr period
during IPR with 3 ABS scores > 21
1. Severity of agitation
Mean of 3 high ABS scores
Mild:
22-28
Moderate:
29-35
Severe:
>36
1. Duration of agitation
Days (first agitated shift in 48-hr period
containing 3 ABS scores > 21) to (last
shift with ABS >21)
4 groups: 0d, (1-10d), (11-25d), >26d
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Presence of agitation
Agitated: at least one 48-hr period
during inpatient stay contained 3
ABS total scores > 21
 Patients with agitation had
 Longer LOS in IPR
 Less frequent discharge home
 Lower motor and cognitive
FIMsTM at discharge
“Cognitive functioning at
admission to IPR
mediates the relationship
between the presence of
agitation and LOS in IPR,
as well as between
agitation and cognitive
functioning at discharge.”
36% of 340 TBI patients were agitated using this definition.
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Severity of agitation
Agitation severity: Mean 3 high ABS
• None
<22
• Mild
22 - 28
• Moderate
29 - 35
• Severe
36 - 56
Bogner et al. 2001
No significant differences based on severity for
• LOS in IPR
• FIMTM motor at discharge
Mild and moderate groups had lower FIMTM cog at
discharge than nonagitated group (difference 2.3)
Severe group did not differ from nonagitated group for
FIMTM cog at discharge
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Duration of agitation
Days (first agitated shift in 48-hr period
containing 3 ABS scores > 21) to (last
shift with ABS >21)
4 groups: 0d, (1-10d), (11-25d), >26d
Bogner et al. 2001
LOS in IPR
• Equivalent for 0d, 1-10d agitation
• ~LOS +12d for 11-25d agitation
• ~LOS +41d for >26d agitation (& not dc to home)
FIMsTMs at discharge
• Motor & Cog equivalent for 0d, 1-10d, 11-25d groups
• FIMTM cog –3.6 for >26d agitation
• FIMTM motor –8.9 for >26d agitation
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Revisit effects of agitation intensity, duration
and density
 New sample of 284 patients
 Characterize agitation as continuous variable
 Agitation intensity = Bogner’s severity
 Agitation duration = 3 alternative definitions
 Agitation density = 4 alternative definitions
 Agitated Bout = Time period over which 6
consecutive shifts had at least 3 ABS scores >21
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Agitation Intensity
 Intensity.1
Mean of 3 highest ABS scores
Range: 14 – 56
Intensity ~ peak agitation
http://www.peakfreaks.com/everestclimbphotos.htm
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Agitation Duration
 Duration.1
Number of shifts in longest bout
Range: 0 – 3*LOS in IPR
shortest
 Duration.2
Number of shifts from first
agitated shift of first bout to last
agitated shift of last bout
Range: 0 – 3*LOS in IPR
 Duration.3
Number of agitated shifts from
first agitated shift of first bout
to last agitated shift during IPR
Range: 0 – 3*LOS in IPR
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longest
Agitation Density
 Density.1
Number of bouts
Range: 0 – LOS in IPR/2
 Density.2
shortest
Number of agitated shifts
within all bouts
Range: 0 – 3*LOS in IPR
 Density.3
Number of agitated shifts
during IPR
longest
Range: 0 – 3*LOS in IPR
 Density.4
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Normalized density:
Avg number of agitated shifts per day =
Density.3/LOS in IPR
Range: 0 – 3
Methods
 Design: Prospective, observational
 Setting: Multidisciplinary acute inpatient rehab
 Participants: 284 consecutively admitted patients
meeting criteria for participation in the NIDRR-funded
TBI Model Systems National Database (10 excluded)
 Instruments: Agitated behavior scale (ABS) scores
during each shift of IPR. Computed agitation Density,
Duration and Intensity constructs
 Demographic variables: Age, Gender, Race,
Education level, Admission GCS, LOS acute, FIM
Motor and Cognitive scores at IPR admission
 Outcomes: LOS in acute IPR, FIM Motor and FIM
Cognitive scores at discharge from IPR
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Sample Characteristics

MA Bockbrader1, D Mortimer2, L Worthen-Chaudhari1, J Rosenthal1, JD Corrigan1, WJ Mysiw1, JA Bogner1
TBI severity, based on initial GCS

1Physical
Medicine & Rehabiitation, The Ohio State University – Columbus, OH; 2Physical Medicine & Rehabilitation, Hennepin County Medical Center - Minneapolis, MN
Mild (GCS 13-15)
Moderate (GCS 9-12)
Severe (GCS 3-8)
Uncategorizable (GCS 3T)
Race
LOS IPR
FIMTM Cog discharge
FIMTM Motor discharge
White
Black
Asian/PI
Native Amer
Hispanic
Other
Gender
207
67
Outcome Means (SD)
20.4 (13.9) days
25.2 (4.2)
70.7 (14.2)
• 41% of TBI patients (n=112) had at least one agitated shift.
• One-third (n=85) had at least one agitated bout.
Education
<HS
HS grad
>HS
+ correlation
Results
- correlation
Agitated Behavior Scale Constructs & Regression Analyses
Clinical bout of agitation - “time period over which any 6 consecutive shifts had 3 or more ABS total scores > 21”
Duration
Agitation Construct Definition
Mean (SD)
*p<0.05
% variance accounted for (R2) by
Significant* Univariate Predictors of:
% variance accounted for (R2) by
Significant* Multivariate Predictors of:
FIMTM Cog
discharge
FIMTM Cog
discharge
FIMTM Motor
discharge
LOS IPR
(days)
FIMTM Motor
discharge
LOS IPR
(days)
Duration.1 # shifts in longest bout
Duration.2 # shifts from first agitated shift of first
bout to last agitated shift of last bout
6.8 (15.5)
11.1 (26.8)
7%
14%
2%
8%
21%
33%
-
2%
-
Duration.3 # shifts from first agitated shift of first
bout to last agitated shift
14.6 (31.1)
16%
9%
37%
-
-
10%
Agitation Construct Definition
# bouts of agitation
# agitated shifts within all bouts
# agitated shifts during IPR
average # agitated shifts per day,
calculated as Density.3/LOS IPR
Mean (SD)
0.5 (0.8)
4.6 (10.5)
5.8 (11.3)
0.2 (0.3)
13%
8%
12%
11%
7%
2%
5%
NS
28%
24%
31%
12%
-
-
3%
Intensity
Agitation Construct Definition
Intensity.1 mean of 3 highest shift scores
Demographic variables
Age
Gender
Race (white, nonwhite)
Education level
Admission GCS group
FIMTM Cog admission
FIMTM Motor admission
LOS acute care
Mean (SD)
22.3 (8.7)
Mean (SD)
37.2 (16.7)
16.4 (6.8)
39.4 (18.1)
16.4 (14.5)
11%
1%
22%
-
3%
-
NS
2%
NS
NS
NS
44%
17%
5%
4%
NS
NS
NS
NS
9%
38%
20%
NS
NS
NS
NS
NS
43%
53%
29%
3%
1%
44%
-
5%
38%
5%
2%
53%
5%
Density
Density.1
Density.2
Density.3
Density.4
Discussion
• In univariate regression analyses, Agitation Density, Duration and Intensity were
significant predictors of rehab LOS and discharge FIMsTM.
• As has been shown previously (Bogner et al. 2001), the relationship between agitation and
discharge Cognitive FIMTM was mediated by admission Cognitive FIMTM.
• Agitation Intensity & Duration were significant independent predictors of discharge
Motor FIMTM (even after accounting for patient age, acute hospital LOS, and admission Motor
FIMTM).
• Agitation Duration and Density were significant independent predictors of rehab LOS
(even after accounting for admission Motor and Cognitive FIMsTM and acute hospital LOS).
• Agitation Duration accounted for 10% of the variability in rehab LOS
Conclusions
1. Constructs that take into account ABS scores over shifts yield
Duration, Density and Intensity measures of agitation. Some of these
provide additional predictive power (over admission FIMsTM and
demographics) for TBI outcomes.
1. Agitation Duration, Density, and Intensity may be important targets for
intervention and relevant adjustments to case-mix groups to more
accurately characterize the resources needed to achieve optimal
rehabilitation outcomes.
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References
 Bogner JA, Corrigan JD, Fugate L, Mysiw WJ, Clinchot D. Role of
agitation in prediction of outcomes after traumatic brain injury. Am J
Phys Med Rehabil 2001;80:636-44.
 Bogner JA, Corrigan JD. Epidemiology of agitation following brain
injury. NeuroRehabilitation 1995;5(4):293-7.
 Corrigan JD. Development of a scale for assessment of agitation
following traumatic brain injury. J Clin Exp Neuropsychol 1989;11:26277.
 Dodds TA, Martin DP, Stolov WC, Deyo RA. A validation of the
functional independence measurement and its performance among
rehabilitation inpatients. Arch Phys Med Rehab 1993;74(5):531-6.
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