Abstract

Objective: To determine the impact of preexisting illness on inpatient rehabilitation outcomes in patients with TBI. Method: Retrospective analysis of prospectively collected data from a TBI Model System Center, inpatient rehabilitation center. Participants included 132 TBI survivors aged ≥ 16. Outcome measures: FIM total score and DRS at discharge, Trail Making Test A (TMT: A), Trail Making Test B (TMT: B), and Total Trials 1–5 of California Verbal Learning Test, 2nd Edition (CVLT-II). Results: Five linear regression models were formulated for FIM, DRS, TMT: A, TMT: B, and CVLT-II, correcting for demographics and injury severity (α = 0.15). Stepwise regression analysis revealed the subset of predictors that produced the best predictive model. Patients who had premorbid history of hypertension or heart condition demonstrated worse functional outcomes by discharge (FIM). A history of cardiac or respiratory condition prior to TBI was associated with reduced cognitive flexibility (TMT: B). Those with premorbid diabetes demonstrated poorer visual attention, visuomotor processing speed (TMT: A), and ability to learn and recall verbal information (CVLT-II). Demographic, severity, and premorbid health variables explained a moderate amount of variance in FIM, DRS, & executive functioning outcomes measured by TMT: B (R2 = 0.52; 0.43; 0.48, respectively). Conclusion(s): Identification and early treatment of these premorbid conditions is important because TBI patients with premorbid hypertension or cardiac condition have greater difficulty with ADLs at the time of discharge from inpatient rehabilitation, and cerebrovascular risk factors and respiratory insufficiency are predictive of poorer neurocognitive functioning and physical dependence beyond the effects of TBI.

Table 1.

Patient Characteristics & Functional and Neuropsychological Measurements

Characteristics/Measure Mean ± S.D. or % Range (Min. to Max. 
Age (years) 45.7±21 16 to 96 
Gender - Male 57% 
Minority 71.3% 
Married 33% 
Interval between injury 17.5±13.8 4 to 30 
to rehab admission   
(days)   
Length of rehab stay 13.6±7 2 to 78 
(days)   
PtA (days) 15.34 ±18 0 to 130 
Discharge to home 93% - 
FIM at discharge 92.5±17 25 to 122 
DRS at discharge 5.6±2 0 to 15 
TMT: A 31.6 ±15 1 to 72 
TMT: B 31.1 ±13 1 to 57 
CVLT-II 34.2 ±18 6 to 78 
Characteristics/Measure Mean ± S.D. or % Range (Min. to Max. 
Age (years) 45.7±21 16 to 96 
Gender - Male 57% 
Minority 71.3% 
Married 33% 
Interval between injury 17.5±13.8 4 to 30 
to rehab admission   
(days)   
Length of rehab stay 13.6±7 2 to 78 
(days)   
PtA (days) 15.34 ±18 0 to 130 
Discharge to home 93% - 
FIM at discharge 92.5±17 25 to 122 
DRS at discharge 5.6±2 0 to 15 
TMT: A 31.6 ±15 1 to 72 
TMT: B 31.1 ±13 1 to 57 
CVLT-II 34.2 ±18 6 to 78 

Mean scores on Neuropsych measures fell in the mildly-to-moderately impaired range.

Table 2.

Pre-Injury Health Status

Condition Response Frequency Condition Response Frequency 
Heart Condition Yes/No 121 14 Emphysema, Yes/No 5.5 
HTN/ High BP Yes/No 38 25.9 asthma, COPD    
Alcohol Consumed > 3 drinks 32 23.4 Cancer Yes/No 
 < 3 drinks 55 40.2 Stroke Yes/No 
 No 50 36.5 Liver Disease Yes/No 1.4 
Illicit Drug Use Yes/No 23 15.5 Diabetes/High BS Yes/No 14 9.5 
Condition Response Frequency Condition Response Frequency 
Heart Condition Yes/No 121 14 Emphysema, Yes/No 5.5 
HTN/ High BP Yes/No 38 25.9 asthma, COPD    
Alcohol Consumed > 3 drinks 32 23.4 Cancer Yes/No 
 < 3 drinks 55 40.2 Stroke Yes/No 
 No 50 36.5 Liver Disease Yes/No 1.4 
Illicit Drug Use Yes/No 23 15.5 Diabetes/High BS Yes/No 14 9.5 

Frequencies and %'s reflect Yes responses; BS = Blood sugar, EtOH was based on # of drinks consumed per sitting.

Table 3.

Demographic, Severity, & Health Predictors Associated with Functional and Neuropsychological Outcomes

Predictors FIM DC DRS DC TMT: A TMT:B CVLT-II 
Fxn'l Status @ Admit Worse Worse Worse Worse NS 
Married NS NS NS Worse NS 
Caucasian Better NS NS Better NS 
Longer LOS Better NS NS NS Better 
PTA NS Worse NS NS Worse 
DC to Home NS Better NS NS NS 
HTN/ High BP Worse NS NS NS NS 
Heart Condition Worse NS NS Worse NS 
Stroke NS NS NS NS NS 
DM/High BS NS NS Worse Better Worse 
Emphysema, asthma, COPD NS NS NS Worse NS 
Cancer NS NS NS NS NS 
EtOH Consumed NS NS NS NS NS 
Illicit Drug Use NS NS NS NS NS 
Predictors FIM DC DRS DC TMT: A TMT:B CVLT-II 
Fxn'l Status @ Admit Worse Worse Worse Worse NS 
Married NS NS NS Worse NS 
Caucasian Better NS NS Better NS 
Longer LOS Better NS NS NS Better 
PTA NS Worse NS NS Worse 
DC to Home NS Better NS NS NS 
HTN/ High BP Worse NS NS NS NS 
Heart Condition Worse NS NS Worse NS 
Stroke NS NS NS NS NS 
DM/High BS NS NS Worse Better Worse 
Emphysema, asthma, COPD NS NS NS Worse NS 
Cancer NS NS NS NS NS 
EtOH Consumed NS NS NS NS NS 
Illicit Drug Use NS NS NS NS NS 

NS = outcomes not significant; LOS = length of stay; PTA = post traumatic amnesia; DC = discharge; HTN = hypertension; DM = diabetes mellitus