Rehabilitation Psychology
August 2000 Vol. 45, No. 3, 260-273
© 2000 by the Educational Publishing Foundation
For personal use only--not for distribution.
Do Neurocognitive Ability and Personality Traits Account for Different
Aspects of Psychosocial Outcome After Traumatic Brain Injury?
David J. Schretlen
Department of Psychiatry and Behavioral Sciences Johns Hopkins University School
of Medicine
ABSTRACT
ABSTRACT. Objective: To examine the contributions of demographic, injury,
cognitive, and personality characteristics to psychosocial outcome 8 years after
traumatic brain injury (TBI). Design: Multiple regression analyses were used to
estimate the variance explained by putative "predictors" of psychosocial outcome.
Participants: Thirty-nine TBI survivors and 39 family member informants. On the
basis of Glasgow Coma Scale scores and Accident Injury Severity (head) ratings, the
patients' brain injuries ranged from mild to critical in severity. Main Outcome
Measures: One self-report measure combined putative markers of social role
engagement, such as marital status and earned income. Another, based on informant
ratings using the Katz Adjustment Scale, was conceptualized as reflecting behavioral
adjustment. Results: Whereas cognitive functioning explained significant unique
variation in social role engagement, it did not account for variance in behavioral
adjustment. Conversely, whereas 3 personality trait ratings explained significant
incremental variance in behavioral stability, only 1 did the same with respect to social
role engagement. Conclusions: Social role engagement and behavioral adjustment
appear to represent 2 related but distinguishable aspects of TBI outcome that are
associated with different patient characteristics.
Many follow-up studies of traumatic brain injury (TBI) have used the Glasgow
Outcome Scale ( Jennet & Bond, 1975 ), Rancho Los Amigos Scale ( Hagen, 1982 ),
or Disability Rating Scale ( Rappaport, Hall, Hopkins, Belleza, & Cope, 1982 ) to
assess outcome. These measures combine such disparate outcomes as death, return to
work, self-care, mobility, psychiatric morbidity, and cognitive impairment into single
measures of global outcome. Although valuable, these scales do not differentiate
among dimensions of outcome. As a result, they may obscure correlations between
specific outcome domains and other patient or injury characteristics. Some studies
have examined TBI outcome in terms of return to work, marital status, and need for
psychiatric treatment ( Bayless, Varney, & Roberts, 1989 ; Brooks, McKinlay,
Symington, Beattie, & Campsie, 1987 ; Fabiano & Crewe, 1995 ; Oddy, Coughlan,
Tyerman, & Jenkins, 1985 ; Ruff et al., 1993 ; Thompsen, 1984 ). These can be
conceptualized as studies of social role engagement. Others have emphasized selfreported emotional and behavior problems ( Diamond, Barth, & Zillmer, 1988 ;
Dikmen & Reitan, 1977 ; Levin & Grossman, 1978 ) or informant ratings of social
adjustment ( Fordyce, Roueche, & Prigatano, 1983 ; Hinkeldey & Corrigan, 1990 ;
Klonoff, Costa, & Snow, 1986 ). These can be conceptualized as studies of behavioral
adjustment.
Relatively few studies have examined long-term outcomes after TBI in terms of both
social role engagement and behavioral adjustment. In one such study, Bowman (1996)
found that demographic and neurocognitive test performance accounted for more
variance in long-term occupational outcome than in everyday behavioral impairment.
Conversely, self-rated emotional problems accounted for more variance in everyday
activity impairment than in occupational functioning. Initial injury severity accounted
for relatively little variance in either outcome measure. These results suggest that
demographic, injury severity, cognitive, and emotional variables affect different
dimensions of psychosocial outcome after TBI to varying degrees. Of course, selfreported emotional distress measured by the Minnesota Multiphasic Personality
Inventory-2 ( Hathaway & McKinley, 1989 ) has been conceptualized as an outcome
of TBI in many previous studies. Whether personality trait characteristics that are
little affected by the development of psychiatric illness also account for some
aspect(s) of long-term psychosocial outcome remains unclear.
Although measures of injury severity, such as the Glasgow Coma Scale (GCS;
Teasdale & Jennett, 1974 ) and duration of posttraumatic amnesia, have been shown
to predict psychosocial outcome after TBI, these relationships can be weak or
diminish over time ( Bond, 1976 ; Bowman, 1996 ; Brooks et al., 1987 ; Dikmen,
Machamer, Temkin, & McLean, 1990 ; Goran, Fabiano, & Crewe, 1997 ). Injury
severity and subsequent cognitive performance both predict return to work ( Bowman,
1996 ; Klonoff et al., 1986 ; Ruff et al., 1993 ). But which demographic and injury
characteristics are most relevant to specific aspects of psychosocial outcome also
remains unclear.
This study investigated two aspects of psychosocial outcome (social role engagement
and behavioral adjustment) in light of demographic, injury severity, neurocognitive,
and personality trait characteristics among patients who had sustained TBIs 8 years
earlier. Executive cognitive abilities were emphasized because they are thought to be
particularly relevant to everyday functioning among patients with TBI ( Lezak, 1995
). The first hypothesis was that cognitive test performance and personality trait
characteristics would explain significant variance in psychosocial outcome after TBI,
even after accounting for the contributions of demographic characteristics and initial
injury severity. The second was that the Social Role Engagement (SRE) Interview,
developed for this study, and overall ratings on the Katz Adjustment Scale (KAS)
would demonstrate related but distinguishable aspects of everyday functioning, as
reflected by different patterns of association with demographic, injury,
neurocognitive, and personality trait variables.
METHOD
Participants and Procedure
The 78 adults who participated in this study included 39 patients and 39 informants
who provided collateral information about each patient. The patients were recruited
from a sample of adults who had all sustained TBIs 8 years earlier. Inclusion criteria
were as follows: (a) no history of preexisting psychiatric disorder or substance abuse,
(b) between 16 and 45 years of age at injury, (c) admission to Johns Hopkins Hospital
or the University of Maryland Shock Trauma Unit within 24 hr of injury, (d) injury
not due to assault, and (e) an Abbreviated Injury Scale (AIS head; Association for the
Advancement of Automotive Medicine, 1980 ) severity rating of 2—5. The patients
were mostly young ( M = 25.7 years at injury, SD = 7.5), Caucasian (90%) men
(74%), of whom 69% had completed 12 years of school or more. At follow-up, they
ranged in age from 23 to 53 years ( M = 33.3, SD = 7.5). Three of these variables (sex,
age at injury, and years of education) were used for statistical analyses of functional
outcome.
The patient informants ranged from 19 to 66 years of age at follow-up ( M = 43.8, SD
= 13.0). Most were Caucasian (90%) women (74%), of whom 75% had completed 12
years of school or more. For 46% of the patients, the informant was a spouse or
partner; 33% were parents, 13% were friends, and the rest were siblings or "other"
(8%). Informants had known their TBI patient counterparts for a mean of 20 years (
SD = 11, range = 2—41). More than 78% knew their patient counterpart before the
injury, and only 4 informants reported less than daily contact.
Patients and their respective informants were seen on the same day. Written informed
consent was obtained from all participants; patients were paid $30, and informants
were paid $10, for their participation. Patients were asked, via the SRE Interview, a
series of questions about their postinjury psychosocial history, after which they
completed a battery of cognitive and personality tests. Informants were asked to rate
their patient counterparts using the SRE Interview, as well as the NEO Personality
Inventory ( Costa & McCrae, 1985 ) and the KAS ( Katz & Lyerly, 1963 ). Neither
outcome measure (SRE Interview or KAS) included any questions about injury
severity, and both were scored without reference to injury severity or any predictor
measure.
Injury severity.
Measures of injury severity included admission GCS scores, AIS head ratings, and
length of initial hospitalization in days. Admission GCS ( Teasdale & Jennett, 1974 )
scores were recorded for 31 patients ( M = 10.3, SD = 4.6). Twelve of these scores
were in the severe range (3—7), 4 were moderate (8—12), and 15 were mild (13—
15). Initial hospitalizations ranged from 3 to 190 days ( M = 44, SD = 47). The AIS
yields ratings of injury severity that range from 1 (no or minor) to 6 (unsurvivable) for
each of eight body regions. Only AIS head ratings were used for the present study.
These ratings were based on information gathered from each patient's medical record
at discharge, incorporated evidence of diffuse or focal brain injury, and ranged from 2
to 5, with a mean of 3.7 ( SD = 1.2). On the basis of AIS ratings, the head injuries of
12 patients were rated as critical; those of the remaining 27 were equally distributed
(i.e., 9 each) among the three categories of severe, serious, and moderate. Because
GCS scores were unavailable for 8 patients, and many other factors can determine
length of initial hospitalization, AIS head ratings were used as the primary measure of
brain injury severity for the purpose of statistical analyses.
Outcome predictors—correlates.
One set of "predictor" variables included (a) age at injury, (b) sex, (c) education at
injury, and (d) AIS head ratings. Because individual differences on the remaining
measures both precede and are affected by TBI, they are better described as correlates
than predictors of outcome. The Shipley Institute of Living Scale ( Zachary, 1986 )
was used to estimate Wechsler Adult Intelligence Scale—Revised ( Wechsler, 1981 )
Full Scale IQ scores. The other cognitive measures included the Trail-Making Test (
Reitan, 1958 ), a measure of psychomotor speed, visual search, and mental flexibility
for which the number of seconds required to complete each part was recorded; the
Wisconsin Card Sorting Test (WCST; Heaton, 1981 ), a measure of concept formation
and attentional shifting for which the number of conceptual sorts was used for data
analyses; the Tinkertoy Test ( Lezak, 1995 ), a measure of the ability to initiate and
execute a potentially complex activity in the absence of a clearly defined external
goal, for which total scores based on the sum of nine feature scores ( Bayless et al.,
1989 ) were recorded; and the Brief Test of Attention (BTA; Schretlen, 1997 ), a
measure of auditory divided attention for which total scores were recorded.
Finally, each informant rated his or her patient counterpart using Form R of the NEO
Personality Inventory ( Costa & McCrae, 1985 ), which yields scores for the five
personality dimensions of neuroticism, extraversion, openness, agreeableness, and
conscientiousness. Four of these dimensions (neuroticism, extraversion,
agreeableness, and conscientiousness) were used for data analyses. Thus, 14 variables
were entered into regression models to "predict" long-term psychosocial outcome
after TBI. The psychometric characteristics (i.e., reliability and validity estimates) of
these "predictor" measures can be found in the reference for each. All of these
measures have been used in studies of persons with TBI ( Bayless et al., 1989 ;
Dikmen, Machamer, Winn, & Temkin, 1995 ; Segalowitz, Unsal, & Dywan, 1992 ;
Wong, 1999 ). Additional information concerning the psychometric properties of each
also can be found in Lezak (1995) and Spreen and Strauss (1998) .
Outcome measures.
The SRE Interview, developed for this study, consists of 20 factual questions about
social role performance (such as marital and employment status, income earned in the
past year, being licensed to drive a car, number of criminal arrests since injury, and
hospital admissions for psychiatric treatment since injury). A numerical score based
on the weighted sum of responses given by each patient was computed such that
higher scores reflected greater and more successful social role engagement. 1
Psychometric characteristics of the SRE Interview are described in the Results
section.
An informant also rated each patient's everyday behavior on the KAS ( Katz &
Lyerly, 1963 ). Although the KAS was developed as a measure of psychosocial
adjustment for patients with psychiatric disorders, it has been used in studies of TBI (
Fordyce et al., 1983 ; Hinkeldey & Corrigan, 1990 ; Oddy, Humphrey, & Uttley, 1978
). The KAS contains 127 behavioral observations for which an informant rates the
patient from 1 ( almost never ) to 4 ( almost always ). Hogarty and Katz (1971)
derived 13 KAS factor scores. For 12 of these (e.g., anxiety, withdrawal, and
suspiciousness), higher scores denote poorer functioning. For Factor 13 (i.e.,
stability), higher scores denote better functioning. In this study, an overall KAS score
based on the sum of ratings across Factors 1—12 (aberrant behaviors) minus each
patient's rating on Factor 13 (behavioral stability) was taken as the primary index of
behavioral adjustment, with higher scores reflecting worse behavioral adjustment.
Separate summary ratings for Factors 1—12 (aberrant behaviors) and Factor 13
(behavioral stability) were used in some analyses. Internal consistency estimates of
KAS factor scores have been found to range from .41 to .87 ( Katz & Lyerly, 1963 ).
Results
Pearson correlation analyses revealed that AIS head scores were associated with GCS
scores ( r = .83, p < .001) and length of hospitalization ( r = .58, p < .001).
Admission GCS scores also correlated ( r = .63, p < .001) with length of
hospitalization. Neither AIS nor length of hospitalization was significantly related to
age at injury, sex, race, or education (all p s > .05).
Basic Characteristics of Patient Outcomes
Patient-reported SRE Interview scores ranged from 2 to 86 ( M = 33.3, SD = 23.1).
They were distributed fairly normally, with a skewness of .40 and a kurtosis of .32,
indicating that the distribution was mildly skewed to the right and slightly leptokurtic
(less peaked than expected). The intraclass correlation coefficient ( Shrout & Fleiss,
1979 ) for 26 pairs of informant and patient reports on the TBI Interview (13
informants did not know their corresponding patient's earned income) was excellent
(equation [3, 1] ICC = .87). The high level of agreement between patient and
informant responses to the SRE Interview probably reflects the factual nature of the
questions. Data concerning the test—retest reliability of this instrument are not yet
available.
Concurrent validity of the SRE Interview scores was explored in terms of both item
content and correlation with the KAS. On the basis of discontinuities in the
distribution of SRE Interview scores, three distinct outcome groups were defined by
SRE scores of or below 20, 21—44, and 45 or above, reflecting poor ( n = 11), fair ( n
= 15), and good ( n = 13) outcomes, respectively. As expected, the three outcome
groups clearly differed in terms of marital and employment status, earned income,
being licensed to drive an automobile, and incidence of psychiatric hospitalization.
Thus, the SRE Interview distinguishes among patients in ways that reflect meaningful
differences in social role engagement, thereby supporting the content validity of this
measure. These findings are shown in Table 1 . Furthermore, although SRE Interview
scores did not correlate with overall KAS ratings ( r = .25, p = .12), they did
correlate significantly with scores on the KAS behavioral stability factor ( r = .48, p =
.002). These findings support the construct validity of the SRE Interview. They also
confirm the hypothesis that the SRE Interview and KAS measure partially
overlapping but largely distinct aspects of psychosocial outcome.
As expected, measures of initial injury severity showed modest but statistically
significant correlations with long-term outcome. Specifically, AIS head ratings
correlated significantly with overall KAS ratings ( r = .28, p = .04, one-tailed) and
marginally with SRE Interview scores ( r = .26, p = .053, one-tailed). Length of
initial hospitalization correlated with SRE Interview scores ( r = .33, p = .02, onetailed) but not with KAS ratings ( r = .20, ns ).
Multiple Regression Models of Concurrent Psychosocial Outcome
Hypotheses regarding the relative contributions of demographic, injury, severity,
personality trait, and cognitive variables to behavioral adjustment and social role
engagement after TBI were tested via hierarchical, stepwise multiple regression
analyses. Predictor variables were grouped into three blocks and made available for
model building according to the position they were hypothesized to occupy in the
causal sequence of psychosocial outcome. Thus, four demographic and clinical
variables (age and education at injury, sex, and AIS head ratings) were grouped
together in Block 1, four NEO personality trait scores (neuroticism, extraversion,
agreeableness, and conscientiousness) were grouped in Block 2, and six cognitive test
scores (IQ, Trail-Making Test Parts A and B, WCST conceptual sorts, BTA, and
Tinkertoy Test scores) were grouped in Block 3. Within each block, variables were
entered stepwise according to the criterion of an F -to-enter at p < .05.
Behavioral adjustment.
In the first regression analysis, overall KAS ratings were regressed on the three blocks
of predictor variables just described. The results of this analysis are summarized in
Table 2 . As shown, not a single variable from Block 1 met entry criteria, whereas
three NEO Personality Inventory trait ratings each improved the model fit. Thereafter,
none of the neurocognitive test scores explained significant additional variance in
behavioral adjustment. Thus, three NEO Personality Inventory trait scores yielded a
highly significant, F (3, 35) = 15.34, p < .001, model that accounted for 57% of the
variance ( R 2 = .568) in overall KAS ratings. As shown in Table 2 , the beta weights
for all three predictor variables were significant, and their signs revealed that better
behavioral adjustment was associated with lower trait neuroticism, higher
agreeableness, and higher conscientiousness. In a follow-up multiple regression
analysis not shown in Table 2 , when all of the demographic and injury severity
variables were forced into the equation, they yielded a nonsignificant model that
accounted for about 10% of the outcome variance. Thereafter, the same three NEO
Personality Inventory variables met entry criteria (according to the stepwise procedure
described earlier), and the resulting model accounted for 61% of the outcome variance
(i.e., less than 5% more than that explained by the three NEO Personality Inventory
scores alone).
Social role engagement.
In the second analysis, SRE Interview scores were regressed on the same three blocks
of predictor variables after identical variable entry procedures. This analysis revealed
a very different pattern of findings. First, three variables from Block 1 (AIS ratings,
education, and sex) met entry criteria, after which one variable from Block 2 (trait
neuroticism) and one variable from Block 3 (BTA scores) also met entry criteria and
improved the model fit. Thus, in this analysis, five predictor variables yielded a highly
significant, F (3, 35) = 8.52, p < .001, model that accounted for 56% of the variance
(adjusted R 2 = .563) in social role engagement. As shown in Table 3 , the final beta
weights remained significant for all but one predictor, NEO neuroticism scores. The
signs of statistically significant beta weights indicate that better social role
engagement was associated with less severe head injuries, more years of education at
injury, male gender, and better cognitive test performance.
In a final series of exploratory analyses, SRE Interview and overall KAS ratings were
regressed on the same 14 variables described earlier, with all variables grouped in a
single block, again using a stepwise method of variable entry. For overall KAS
ratings, this procedure yielded results that were identical to those described earlier:
The same three NEO Personality Inventory trait T scores met entry criteria for a
model with an R 2 value of .57. Consequently, these results are not shown in a separate
table. For SRE Interview scores, in contrast, when all 14 predictor variables were
grouped together for stepwise entry, a very different model emerged. Specifically, just
three variables met entry criteria for a highly significant, F (3, 35) = 11.54, p < .001,
model that accounted for 50% of the variance ( R 2 = .50) in social role engagement.
As shown in Table 4 , these three "predictor" variables included performance on the
BTA, total score on the Tinkertoy Test, and age at injury. Thus, absent the a priori
hierarchical ordering of potential predictor variables, terms for sex, injury severity,
and personality trait characteristics did not enter the equation, whereas the
contribution of cognitive test performance became more evident.
Discussion
Several findings emerged from this study. First, the SRE Interview and KAS
behavioral stability factor score yielded moderately correlated measures of
psychosocial outcome. The content validity of the SRE Interview also was supported
by the finding that three outcome groups defined by it differed in ways that obviously
reflect the adequacy of social role engagement, such as earned income, marital status,
and being licensed to drive an automobile. They also differed in terms of behavioral
stability (but not aberrant behavior) as measured by the KAS. These findings suggest
that social role engagement and behavioral adjustment represent partially overlapping
aspects of psychosocial outcome after TBI.
Second, despite the moderately strong correlation between SRE Interview scores and
KAS Factor 13 (behavioral stability) ratings, the fact that only 25% of the variance in
each was shared by the other suggests that they tap different aspects of outcome.
Other findings also support this inference. For example, SRE Interview scores did not
correlate significantly with either overall KAS ratings or the summed ratings for KAS
Factors 1—12 (aberrant behaviors).
Third, further evidence that social role engagement and behavioral adjustment
represent distinguishable aspects of outcome emerged from multiple regression
analyses. These analyses showed that SRE Interview scores and overall KAS ratings
were best explained by very different variables. Behavioral adjustment, as measured
by overall ratings on the KAS, was best explained by informant ratings of personality
trait neuroticism, agreeableness, and conscientiousness. Each of these accounted for
significant unique variance in behavioral adjustment, whereas age, sex, education,
injury severity, and cognitive test performance did not. In contrast, adequacy of selfreported social role engagement, as measured by SRE Interview scores, was best
explained by a combination of five variables: years of education at injury, sex, injury
severity, trait neuroticism, and cognitive test performance. Not only did personality
trait ratings account for relatively little variance in social role engagement, the beta
weight for neuroticism was attenuated to a nonsignificant level by entering a term for
cognitive test performance.
A fourth finding was that preinjury level of education and measures of injury severity
made statistically significant but relatively modest contributions to models accounting
for psychosocial outcome 8 years later. This is consistent with previous findings that
the relationship between injury severity and outcome can be relatively weak or
diminish over time ( Bond, 1976 ; Brooks et al., 1987 ; Dikmen et al., 1990 ; Goran et
al., 1997 ).
In this study, social role engagement was more strongly associated with concurrent
cognitive test performance than with injury severity or personality characteristics.
Given the inclusion of employment status and earned income in the measure of social
role engagement, these findings are strikingly similar to those obtained by Bowman
(1996) and Goran et al. (1997) , both of whom found that measures of concurrent
intellectual ability were more predictive of return to work than were length of coma or
overall injury severity among TBI survivors. For example, using a stepwise multiple
regression procedure, Bowman (1996) found that neurocognitive test performance
accounted for 21% of the variance, as compared with 2% for injury severity, in
occupational attainment 3—4 years after TBI. The finding that heightened
distractibility, as measured by the BTA, was especially related to worse social role
functioning in the present study also is consistent with previous findings that low
scores on the same test were associated with functional disability among psychiatric
patients ( Schretlen et al., 2000 ) and an increased 2-year incidence of vehicular
accidents among elderly drivers ( Keyl, Rebok, & Gallo, 2000 ). In short, in the
present study, patients who were more educated at the time of injury, less distractible
at follow-up, and lower in trait neuroticism were more likely to be employed, married,
and licensed to drive and more likely not to have required psychiatric hospitalization
during the 8 years since their initial injury.
Although injury severity and neurocognitive test performance distinguished among
the patient groups defined by KAS ratings of behavioral adjustment, NEO Personality
Inventory factor scores were more closely associated with this dimension of
psychosocial outcome. The most relevant NEO Personality Inventory factor scores
were neuroticism (impulsivity and irritability), agreeableness (trustfulness and
compliance), and conscientiousness (competence and deliberation). Whether these
represent enduring characteristics that preceded each patient's injury or were affected
by the brain injury cannot be determined from this cross-sectional study. Costa and
McCrae (1985) contended that the NEO Personality Inventory measures normal
personality characteristics that are stable over time and relatively insensitive to
circumstance or the onset of psychiatric symptoms. Thus, the observed differences in
NEO Personality Inventory scores among outcome groups might reflect preinjury
personality trait differences that moderate the relationship between injury severity and
long-term behavioral adjustment after TBI. Alternatively, the observed differences in
NEO Personality Inventory trait scores might be jointly determined by premorbid
factors and the effects of TBI. This would be consistent with the observation that
brain injuries often seem to exacerbate preinjury personality vulnerabilities or lead to
a general coarsening of personality ( Prigatano, 1987 ).
Two limitations of this study require comment. First, the variable-to-subject ratio was
somewhat excessive. Although a part of the study design, the a priori selection of
certain variables (e.g., use of WCST categories sorted) and the use of summary scores
(e.g., factor scores from the NEO Personality Inventory) did not eliminate the
problem. A somewhat elevated risk of Type I errors was accepted on the basis that
this investigation was designed to refine the initial hypotheses for further research
rather than to definitively test a specific hypothesis. A second weakness was the
relatively coarse manner in which injury severity was assessed. More precise
quantification of the extent and location of brain tissue injury with neuroimaging or
information about surgical intervention, intracranial pressure, and so forth might have
provided more accurate predictions of long-term outcome than GCS scores, AIS
ratings, and length of hospitalization. Both of these limitations point to areas in which
the study design might be strengthened by future research.
Despite limitations, the obtained results suggest that two broad domains of
psychosocial outcome can be discerned 8 years after TBI. Although these two
domains tap overlapping aspects of everyday functioning, the dimension of social role
engagement was more strongly associated with cognitive abilities than personality. In
contrast, the dimension of behavioral adjustment was most strongly associated with
individual differences in personality. For clinical purposes, these findings suggest that
comprehensive neuropsychological evaluations of patients with TBI ought to include
measures of both neurocognitive functioning and personality. The former can
elucidate rate-limiting targets for rehabilitation interventions that aim to restore
competence in social role functioning, and the latter can reveal personality trait
characteristics that probably contribute to everyday behavioral adjustment.
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1
A copy of the SRE Interview is available from David J. Schretlen on request.
This study was supported by the U.S. Department of Education, National Institute on
Disability and Rehabilitation Research (Grant H133C90054). I gratefully
acknowledge John A. Bates for his assistance with data collection, test scoring, and
data entry.
Correspondence may be addressed to David J. Schretlen, Johns Hopkins Hospital,
Meyer 218, Baltimore, Maryland, 21287-7218.
Electronic mail may be sent to dschret@jhmi.edu
Received: May 24, 1999
Revised: December 5, 1999
Accepted: December 8, 1999
Table 1. Characteristics of Outcome Groups Defined by Responses to the Social Role
Engagement (SRE) Interview
Table 2. Hierarchical—Stepwise Multiple Regression of Overall Katz Adjustment
Scale Ratings (Behavioral Adjustment) on Demographic, Clinical, Personality, and
Cognitive Predictor Variables
Table 3. Hierarchical—Stepwise Multiple Regression of Social Role Engagement
Interview Scores on Demographic, Clinical, Personality, and Cognitive Predictor
Variables
Table 4. Stepwise Multiple Regression of Social Role Engagement Interview Scores
on Demographic, Clinical, Personality, and Cognitive Predictor Variables