Outcomes in the First 5 Years After Traumatic Brain Injury

Transcription

1 298 Outcomes in the First 5 Years After Traumatic Brain Injury John D. Corrigan, PhD, Kip Smith-Knapp, PhD, Carl V. Granger, MD ABSTRACT. Corrigan JD, Smith-Knapp K, Granger CV. Outcomes in the first 5 years after traumatic brain injury. Arch Phys Med Refiabil 1998;79: Objective: To examine the extent to which outcomes from traumatic brain injury differ as a function of time and can be predicted at discharge from inpatient rehabilitation. Design: Survey method employing cross-sectional analyses. Setting: An inpatient brain injury rehabilitation unit in a large midwestern academic medical center. Subjects: Ninety-five adults with traumatic brain injuries, 6 months to 5 years after inpatient rehabilitation, stratified by time postdischarge. Main Outcome Measures: Functional Independence Measure (FIMSM), Sickness Impact Profile (SIP), Medical Outcomes Survey SF-36, Community Integration Questionnaire (CIQ), Craig Handicap Assessment and Reporting Technique (CHART), Brief Symptom Inventory (BSI), Satisfaction With Life Scale (SWLS), and indices of current psychosocial functioning. Results: Substance abuse, need for supervision, life satisfaction, and selected subscales of the CIQ and CHART differed over the period 6 months to 5 years after discharge. Approximately 75% of the variance in current FIM scores, and 40% to 50% of CHART, CIQ, and SIP total scores, could be predicted at time of discharge. Conclusions: Outcomes over the first 5 years after discharge were dynamic, with most change being improvement, at least after the first 2 years. Important aspects of outcome could not be predicted based on premorbid characteristics, injury severity, and initial functional abilities by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation HERE IS A SMALL BODY of literature that examines T later outcomes from traumatic brain injury in civilian populations. The longest-duration studies have been longitudinal evaluations of relatively small cohorts identified in several European medical centers. 1-3 The longest-term follow-up was conducted by Thomsen, 1 who reported outcomes on a group of From the Department of Physical Medicine and Rehabilitation, The Ohio State University, Columbus, OH (Dr. Corrigan); the Department of Physical Medicine and Rehabilitation, Medical College of Ohio, Toledo, OH (Dr. Smith-Knapp); and the Depam~ent of Rehabilitation Medicine, State University of New York at Buffalo, Buffalo, NY (Dr. Granger). Submitted for publication February 17, Accepted in revised form October 9, Supported in part by grant HI33B30041 from the National Institute on Disability and Rehabilitation Research to the Rehabilitation Research and Training Center on Functional Assessment and Evaluation of Rehabilitation Outcomes, Department of Rehabilitation Medicine, SUNY Buffalo; and grant H235L20001 from the US Depamnent of Education, Rehabilitation Services Administration, to the Ohio Valley Center for Brain Injury Prevention and Rehabilitation, Columbus, OH. No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the authors or upon any organization with which the authors are associated. Reprint requests to John D. Corrigau, PhD, Dodd Hall, 480 West 9th Avenue, Columbus, OH by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation / /0 patients 15 years after injury. Thomsen observed that severity of the original injury, age of the individual, premorbid personality, stability of family background, and occupational level at time of injury were significant contributing factors to eventual outcome. Patients with the most severe disability showed little improvement from early to late follow-up and continued to have problems with social isolation, behavior, caregiver stress, and unemployment. A similar pattern was reported by Oddy and colleagues, 2 who studied a group of patients initially treated in a London hospital and who were followed for 7 years. Little improvement was noted from the 2nd to the 7th year of evaluation. There were only trends toward improved physical function, and there was little change in cognitive ability. While persons who were working part-time tended to be able to resume full-time employment, only one individual who had not been working at 2 years was able to work at 7 years. Significant problems persisted in both social and emotional dimensions, with pronounced isolation and caregiver stress. Brooks and colleagues 3 found results similar to those reported by Thomsen and Oddy in a 7-year follow-up of patients treated at their trauma center. In the United States, Jacobs '4,5 reports of results from the Los Angeles Head Injury Survey were landmark contributions to understanding the long-term problems that can result from severe traumatic brain injury. This survey was a cross-sectional study of individuals 1 to 6 years postonset who had incurred severe injury and had received rehabilitation. The survey documented significant long-term negative consequences for both the individual and the family, in terms of vocational outcomes, financial status, and behavioral functioning. In Australia, Olver and associates 6 investigated changes between 2 and 5 years after injury for a cohort of persons treated in one rehabilitation program. Substantial numbers of subjects reported problems with vision, fatigue, cognition, and emotions at both 2 and 5 years, and the number suffering headaches increased. Marital status changed minimally, and independence in activities of daily living and community mobility improved. However, employment status declined--almost one third of those working at 2 years were unemployed at 5 years. The Traumatic Brain Injury Model Systems projects funded by the National Institute on Disability and Rehabilitation Research have reported follow-ups conducted as long as 4 years after injury. Initial reports described outcomes 1 to 2 years after injury, 7'8 with more recent reports including results for those 3 to 4 years after injury. 9'10 Sander and colleagues 9 reported longitudinal outcomes for return to work and community integration among model systems subjects. Less than 40% of their subjects who were employed before injury were employed at any of the three follow-up intervals 1 year, 2 years, and either 3 or 4 years after injury. A majority of those who were employed at initial follow-up remained so at the 3- to 4-year mark, whereas only half of those unemployed initially were able to become productive later. Community integration did not show significant changes over time, with scores remaining below those of nondisabled samples. The persistence of poor outcomes was most evident in terms of productive activity, particularly for older persons. Initial severity of disability was related to later home and social integration. Kreutzer and

2 OUTCOMES AFTER TRAUMATIC BRAIN INJURY, Corrigan 299 colleagues '1 examination of substance use in the model systems cohort indicated that apparent abuse increased from earlier to later follow-up. A similar finding was reported by Corrigan and coworkers 11 in a cohort of persons with substance abuse problems after traumatic brain injury: more than 2 years after injury, the amount of alcohol consumed increased significantly. While studies have identified some consistencies in findings regardless of cohort and time postinjury, the outcomes literature as a whole does not constitute a substantial body of knowledge. Corrigan and colleagues 12 recently warned of the potential for systematic bias in outcome studies in this population because of the apparent greater likelihood that persons with substance abuse problems will be lost to later follow-up. Longitudinal studies have varied in the time to follow-up and have been inconsistent in the extent to which dynamic aspects of change were investigated. There have only been a small number of highly specialized cohorts examined more than a few years after injury, although Model Systems data will be forthcoming for later periods. Finally, although employment, psychosocial functioning, and cognitive impairment have been common outcomes, investigations have not been guided by theoretical schema of the overall nature of outcomes. Thus, issues of causality and/or colinearity have rarely been addressed. In the current study, data available from an investigation of the Functional Independence Measure (FIM) allowed a crosssectional analysis of several characteristics of outcome in the period 6 months to 5 years after injury. These data were collected as part of a study that examined the validity of the FIM as a measure of disability for persons with traumatic brain injury. 13 In the course of data collection, multiple indices of impairment, disability, societal participation (otherwise known as handicap), affective functioning, and subjective well-being were collected on subjects with moderate to severe brain injury who were stratified by time since discharge from acute rehabilitation. Using a cross-sectional approach, we were able to inquire about the extent to which outcomes (1) differ as a function of time postdischarge and (2) can be predicted at the time of discharge. While the results must be considered exploratory, we believe that these analyses contribute to a research literature that is relatively sparse. METHOD Study Sample Subjects were 95 adults who experienced traumatic brain injury and were treated on a specialized brain injury rehabilitation unit in a large midwestern academic medical center. The sample was stratified by time since discharge from inpatient rehabilitation, as follows: 6 months to 1 year postdischarge, 1 to 2 years, 2 to 3 years, 3 to 4 years, and 4 to 5 years. During 16 quarters of data collection, 393 of 536 former patients were selected at random and attempts were made to contact them. Of those contacted, 111 individuals indicated an interest in participating in the study; 95 completed it in its entirety. Eleven subjects were scheduled but either canceled or did not show on more than one occasion; five subjects completed the first interview but did not return for the second. Seventy-six subjects declined to participate, citing different reasons, including pending litigation. Six subjects had died. Twenty subjects were labeled "not available" because they were incarcerated, resided in a nursing home, or were living out of state. Forty-six percent (180 individuals) of the subject pool could not be reached or located. Thus, from the 393 names selected, there was a completion rate of 24%. To examine how this low completion might have biased the resulting sample, premorbid and injury- related characteristics of this sample were compared with a prospective sample of 100 patients with traumatic brain injury admitted to the same unit for rehabilitation. Chi-squares and t tests revealed no significant differences (p <.05) between the samples for gender, prior brain injury, ethnicity, education at injury, age at injury, days of posttraumatic amnesia (PTA), admission FIM Motor, discharge FIM Cognitive, acute hospital length of stay, acute rehabilitation length of stay, and total hospital length of stay. Small but statistically significant differences were evident for admission FIM Cognitive (.29 standard deviation lower) and discharge FIM Motor (.33 standard deviation lower). Instrumentation Psychosocial and injury-related characteristics. Preinjury and current psychosocial characteristics determined from interview were gender, age, ethnicity, marital status, educational level, residence, living arrangement, employment, annual income, use of illicit drugs, use of alcohol, prior brain injury, and rehospitalization since rehabilitation discharge. Information obtained through medical records included date of injury, cause of injury, length of time from injury to acute rehabilitation admission, length of stay in acute inpatient rehabilitation, date of discharge from acute rehabilitation, length of PTA, and rehabilitation admission and discharge FIM scores. Assistance required. The Help at Home Diary 14,15 was used to assess minutes of assistance required during the day. Subjects maintained a record of the help required for personal care activities during a 7-day period. A stopwatch was used to obtain prospective measurements of actual time being assisted when eating, grooming, bathing, dressing, ambulating, and toileting. Results were summarized in a daily average of minutes of assistance. The Supervision Questionnaire for Caregivers 16 was used to assess level of supervision as follows: constant (subject required 24-hour supervision), modified constant (may be left alone 1 to 3 hours); intermittent daily supervision (may be left alone 4 to 7 hours); daily (may be left alone up to 8 hours); periodic (once per week); or none (subject is totally independent). A primary caregiver or, if independent, the individual with the injury responded to these questions. Standardized measures of disability. Three standardized instruments measuring functional abilities were used (the reliability and validity of these instruments are well established). The FIM is an 18-item scale completed by a trained rater. 17 The question and answer format used in the telephone interview version of the instrument was used as stimulus material for ratings. The two component subscales, FIM Motor (13 items) and FIM Cognitive (5 items), were calculated and used in analyses. The Sickness Impact Profile (SIP) is a 136-item scale that assesses functional capabilities following illness and disease. 18 It yields twelve subscales, two summary dimension scores, and a total score. The Total score and two summary dimension subscales, Physical and Psychosocial, were used in analyses. Higher scores indicate a greater impact of "sickness" on activities of daily living. The Medical Outcomes Survey SF-36 is a 36-item measure of functional status related to health. 19 Eight health concepts as perceived by the individual are measured: Physical Functioning, Role Functioning-Physical, Bodily Pain, General Health, Vitality, Social Functioning, Role Functioning-Emotional, Mental Health, and Health Transitions. Raw scores are transformed to a scale score ranging from 0 to 100 such that a higher score indicates better health or less impact of health on functioning. The eight scales were transformed into the Physical Component Summary (comprised of the first four health concepts above) and the

3 300 OUTCOMES AFTER TRAUMATIC BRAIN INJURY, Corrigan Mental Component Summary (consisting of the latter four health concepts). Standardized measures of societal participation. Two standardized measures of societal participation were used in the current study. The Craig Handicap Assessment and Reporting Technique (CHART) is a 30-item scale that produces a total score and five subscales (Physical Independence, Mobility, Social Integration, Economic Self-sufficiency, Occupation) based on the World Health Organization's five dimensions of survival skills, z Scores range from 0 to 100, with a higher score indicating greater societal participation. Test-retest reliabilities have ranged from.80 (Economic Self-Sufficiency) to.93 (Total score). Concurrent validity of the CHART has been demonstrated in comparisons with global ratings made by rehabilitation professionals. The Community Integration Questionnaire (CIQ) was developed to measure role performance in the community. 21 The CIQ is a 15-item scale with three subscales that assesses the extent of community integration in the home, productive activities, and social participation. Higher scores indicate greater integration. Test-retest reliability coefficients for the Total score and subscales have ranged from.83 to The CIQ has been compared to the CHART for evaluation of concurrent validity. 22 While correlations between the two total scores were high (.62 to.70 depending on the rater), relationships between subscales were more variable. For instance, the CHART Social Integration subscale was not correlated with any CIQ subscale, possibly because of the low ceiling of the former. 22 Affective status. Current psychological functioning was assessed using the Brief Symptom Inventory (BSI), a 53-item scale that assesses the nature and extent of psychological distress. 23 Nine symptom dimensions and three global indices are derived from subjects' ratings of the frequency of complaints. Raw scores were transformed into T-scores using the nonpatient adult norms. Internal consistency for the nine symptom dimension scales ranges from.71 to.85. Test-retest reliabilities for a 2-week interval ranged from.68 to.91. Validity of the instrument has been demonstrated by convergence with the MMPI Analyses in the current study were limited to the Global Severity Index and the Depression score. Subjective well-being. Subjects' subjective satisfaction with their current life was assessed using the Satisfaction With Life Scale (SWLS). 24,25 The SWLS has five items with a 7-point Likert-type response format that are added to create a total score ranging from 5 to 35. A score of 20 represents a neutral point at which the respondent is equally satisfied and dissatisfied. The SWLS has consistently demonstrated good internal consistency, and test-retest reliabilities have ranged from.54 for a 4-year interval to.84 for a 2-month interval. 25 Procedures The study population was randomly sampled from individuals discharged from the Traumatic Brain Injury Unit during the previous 5 years. Telephone contact was made to solicit an individual's consent to participate, if selected. If consent was given, the supervision questionnaire was administered by telephone to a significant other or primary caregiver (this step was a relic of the initial intention to stratify by level of supervision required). If there was not an identifiable significant other or primary caregiver, then the subject was considered independent. An appointment was scheduled with the experimenter to complete the demographic interview, CIQ, CHART, SF-36, and FIM, and to provide training in the Help at Home Diary. For those subjects who were not independent, this appointment included a significant other or primary caregiver to verify self-reports and assure understanding of instructions. A second appointment was scheduled for 1 week later, at which time the examiner ascertained that the journal was completed and administered the SIR BSI, and SWLS. Assistance was provided by the examiner in completing instruments to the extent required by the subject. If the subject's self-report differed from the caregiver's report, a decision was made as to which information to record. On items requiring objective information (eg, demographic information, need for and type of assistance), the caregiver's input was assumed to be more accurate in cases of disagreement; for subjective items (eg, life satisfaction, psychological distress) the subject's evaluation was always used. All interviews were conducted by the same examiner, a postdoctoral fellow. Demographic data were collected via patient/caregiver interview. Medical records were reviewed to extract injury-related data. Analyses The first set of analyses examined whether and how outcome indices changed as a function of time postdischarge. For indices with at least ordinal properties, means and standard deviations for each of the five postdischarge time periods were compared using the Kruskal-Wallis test. A nonparametric statistic was used because plots of the residuals did not support the assumption of normality, primarily because of the relatively small number of subjects within categories of time postdischarge. For outcome indices with dichotomous properties, the proportion of subjects in each postdischarge time period was calculated and differences over time were tested using the Trend test. This statistic allowed a specific test of linear change over time intervals and, thus, had more power than 2 analyses. Despite the potential for spurious findings, a p <.05 level of significance was used because of the exploratory nature of the study and a consequent desire to limit Type II error. To examine the extent to which outcomes can be predicted at time of discharge, hierarchical linear regressions were computed for outcome indices with interval properties for which plots of the residuals suggested that deviations from the assumptions of normality were minimal. The Total scores for the SIP, CHART, and CIQ were used because we sought to limit the number of analyses, and the psychometric properties of composite scores were expected to be superior to those of their component subscales. Regressions were also calculated for FIM Motor, FIM Cognitive, SF-36 Physical, SF-36 Mental, SWLS, BSI Global Severity Index, and BSI Depression scores. Predictor variables were those that would be known at discharge from rehabilitation and included both premorbid and injury-related characteristics. Premorbid variables were age, education, gender, ethnicity, employment, income, and prior brain injury. Injury characteristics included as predictors were length of PTA, time to rehabilitation admission, rehabilitation admission FIM Motor and FIM Cognitive scores, rehabilitation discharge FIM Motor and FIM Cognitive scores, and time from rehabilitation discharge to outcome measurement. Variables were forced into the regression in two steps, with all variables except discharge FIM scores comprising the first step, and discharge FIM scores the second. Because of the large number of predictor variables, stepwise regressions could be expected to result in large, statistically significant R z values. Therefore, interpretation was based on the adjusted R 2, a statistic that takes into account the number of predictor variables. 26 RESULTS Of the 95 subjects who completed the study, 66 (70%) were male and 29 (30%) were female. Age at the time of injury

4 OUTCOMES AFTER TRAUMATIC BRAIN INJURY, Corrigan 301 ranged from 14 to 76 years (X = 32.4 yrs); yrs); age at the time of interview ranged from 16 to 80 years (X = 35.2 yrs). Eighty-eight subjects (93%) were Caucasian; 7 (7%) were African-American. Seventy subjects (74%) sustained their injury in moving vehicles (automobiles, motorcycles, bicycles, and all-terrain vehicles) as either passengers or pedestrians; 11 (11%) sustained injury secondary to assaults or other acts of violence; 9 (9%) were injured secondary to falls; 2 (2%) were injured in recreational activities (horseback riding); 2 (2%) were hit by flying or falling objects; and the nature of injury for one individual was never determined. Acute hospital length of stay averaged 46.6 days; inpatient rehabilitation length of stay averaged 49.1 days. Rehabilitation admission FIM Motor averaged 38.8, FIM Cognitive Discharge FIM Motor averaged 75.6, FIM Cognitive Time postinjury ranged from 7 to 65 months (~ = 33.3 too). Seven subjects (7%) required 24-hour supervision, 2 (2%) required modified constant supervision (left alone 1 to 3 hours), 13 (13%) required daily supervision, 6 (6%) required weekly supervision, and 67 (71%) were totally independent. Stratification of time postdischarge from acute rehabilitation yielded the following distribution: 6 to 12 months, 18 subjects (19%); 13 to 24 months, 21 subjects (22%); 25 to 36 months, 18 subjects (19%); 37 to 48 months, 23 subjects (24%); and 49 to 60 months, 15 subjects (16%). Time postdischarge ranged from 6 to 59 months (X ). To allow greater confidence in generalizing cross-sectional findings to longitudinal phenomena, premorbid and injuryrelated characteristics of the five subgroups were compared using the Kruskal-Wallis test, X 2, and Fischer's exact test. Comparisons were conducted on gender, prior brain injury, ethnicity, income at injury, employment at injury, education at injury, age at injury, days of PTA, admission FIM Motor, admission FIM Cognitive, discharge FIM Motor, discharge FIM Cognitive, acute hospital length of stay, acute rehabilitation length of stay, and total hospital length of stay. No significant differences (p <.05) were found between groups for any of the comparisons performed. These results increased the likelihood that differences found in cross-sectional analyses of outcome variables were due to longitudinal processes rather than pre-existing differences among subjects comprising the five subgroups of time postdischarge. Cross-Sectional Analyses Table 1 shows values for the 26 outcome indicators that were analyzed in each of the five postdischarge time periods. Several indices of functional independence approached maximum levels and remained consistent across the 5-year period, including FIM Motor, FIM Cognitive, CHART Physical, and CHART Mobility. Two scales from the BSI, the Global Severity Index and the Depression score, averaged below cutoffs for "caseness" (T score--> 63), although 40% and 36% of subjects exceeded criterion for the Global Severity Index and Depression scale, respectively. The average scores for these scales remained relatively stable across the five time periods. Certain global indices of societal functioning, while not significantly different over the 5-year period, were discrepant from published norms. These indices included the total scores from the SIP, CIQ, and CHART, as well as the SF-36 component scores. Both the CHART and CIQ total scores showed trends toward improving over the 5-year period; in each case, single subscales reached significance. The Physical and Mental component scores from the SF-36 showed marked, poorer scores than norms, although again stable over the 5-year period. Five indices changed significantly over the 5-year period, with four of these showing improvement and the fifth decline. The CHART Occupation scale improved significantly, particularly in the 3- to 5-year range. While the proportion of subjects who were currently productive (in work or school) did not show a significant change, this index declined after the 6-month to 1-year period, followed by consistent improvement over the remaining four periods. The Trend test, which evaluates linear progression, would not be as sensitive to curvilinear change such as that evident for the productivity indicator. The CIQ Home Integration scale also showed significant improvement, although it also declined before marked improvement in the 3- to 5-year range. The Kruskal-Wallis procedure used to test these differences is more sensitive to nonlinear, mean differences than the Trend test. The proportion of individuals needing supervision changed significantly over the 5-year period, again with dramatic increases in independence in the 3- to 5-year range. Although those requiring direct assistance did not show significant change, when the two indicators of need for assistance (direct assistance and supervision) were combined, a significant, steady progression toward independence from any assistance was evident over the 5-year period. The fourth indicator showing significant change over the 5-year period was the SWLS, which also demonstrated a curvilinear pattern, with a decline following the first year. The only indicator showing deterioration over the 5-year period was the proportion of individuals abusing substances. Substance abuse was determined from responses to the amount of alcohol consumed, the frequency with which alcohol was consumed to intoxication, and the use of illegal substances. Alcohol consumption that would qualify as moderate or heavy, multiple intoxications per week, or the use of illegal substances were considered indications of substance abuse. While no subjects in their first 2 postdischarge years were so classified, approximately one fourth of those in each of the three time periods after appeared to be abusing alcohol or other drugs. Multiple Regressions Results of the multiple regressions computed to predict long-term outcomes based on rehabilitation discharges are reported in table 2. Regression equations for 6 of the 10 indices reached statistical significance, and considerable variability was evident. The adjusted R 2 should not be considered as a robust indicator of the amount of variance that can be accounted for, although values for different equations can be compared with confidence. Later FIM Motor and FIM Cognitive scores were highly predictable at rehabilitation discharge, which would be expected given that both FIM admission and FIM discharge scores were included in the prediction equation. Total scores from the three measures of overall societal functioning, the CHART, CIQ, and SIP, showed modest but significant predictability. The Physical and Mental component scores from the SF-36 appeared markedly different than other overall indices of societal functioning; variance accounted for in the SF-36 Physical was less than half that for the CHART, CIQ and SIP total scores, and only a minimum amount of variance from the SF-36 Mental could be predicted. The SWLS, as well as scores derived from the BSI, also showed minimal predictability. DISCUSSION Although this study was exploratory, results indicated that some outcomes in the first 5 years after discharge from rehabilitation may change, while others appear to remain relatively stable. Among those indices that changed, improvement was more common than deterioration; however, an interesting pattern of decline in the first several years followed

5 302 OUTCOMES AFTER TRAUMATIC BRAIN INJURY, Corrigan Table 1: Outcome Indices by lime Postdischarge 6Mo-lYr 1-2Yrs 2-3Yrs 3-4Yrs 4-SYrs FIM Motor Mean 87, , SD FIM Cognitive Mean 31, SD 2,50 3, SIP Total Mean 1, , , , , SD 1, , , , , SIP Physical Mean , SD SIP Psychosocial Mean SD SF-36 Physical Mean SD SF-36 Mental Mean SD , CIQ Total Mean SD 4, CIQ Home Integration* Mean , SD CIQ Social Integration Mean 7, , SD CIQ Productivity Mean SD CHART Total Mean 81,44 73, SD CHART Physical Mean 96,64 92, SD CHART Mobility Mean SD CHART Social Mean ,38 SD CHART Economic Mean , SD CHART Occupation* Mean SD BSI Global Severity Index Mean SD BSI Depression Mean ,81 SD 10, , Table 1: Outcome Indices by "time Postdischarge (Cont'd) 6Mo-1Yr 1-2Yrs 2-3Yrs 3-4Yrs 4-5Yrs Satisfaction With Life Scale* Mean , SD Current Income Mean $10,472 $10,995 $10,628 $17,952 $18,580 SD $10,725 $11,796 $10,379 $16,901 $28,155 Currently productive (%) ,3 Needing direct assistance (%) ,8 Needing supervision* (%) Living independently (%) Rehospitalized (%) Abusing substances* (%) , Total Sample (%) *p<.01. *.01 < p <.05. by later improvement was observed for some indices. There was some variation as well in the ability to predict later outcomes based on information available at the time of rehabilitation discharge. As might be expected, later FIM scores could be predicted relatively well with admission and discharge FIM scores, as well as other injury-related and premorbid indices. General indicators of societal functioning, ie, the total scores from the CIQ, CHART and SIP, showed moderate levels of predictability, although a majority of variance was not accounted for. Outcomes such as life satisfaction, affective status, and role functioning as reflected in the component scores of the SF-36 were minimally predictable. Among outcome measures that were stable over the 5-year period, some averaged within normative levels for comparison groups and others were stable but below normative expectations. Among the former were the FIM Motor and FIM Cognitive scores, which averaged in the independent range. FIM Motor scores approached complete independence, which may support the observation of Hall and colleagues z7 that FIM scores in the Traumatic Brain Injury Model Systems dataset show a substantial ceiling effect at 1-year follow-up. Measures of affective status, ie, the Global Severity Index and the *p <.05. Table 2: Prediction of Later Outcomes Based on Rehabilitation Discharge Outcome Indices Adjusted R 2 FIM-Motor.773" FIM-Cognitive.690" CHART-Total.493" CIQ-Total.452* SIP-Total.417* SF-36 Physical.187" SF-36 Mental.003 SWLS.047 BSI Global Severity Index.068 BSI Depression.116

6 OUTCOMES AFTER TRAUMATIC BRAIN INJURY, Corrigan 303 Depression scale from the BSI, averaged below the cut-off for "caseness"; however, relatively high proportions of subjects exceeded the criterion (40% for the Global Severity Index and 36% for the Depression scale). With regards to depression, this case rate is consistent with several previous studies; however, the reported incidence of depression after traumatic brain injury has varied widely depending on the severity of the sample, time period assessed, and method of assessment General indices of societal functioning, ie, the CIQ, CHART, SIR and SF-36, were also relatively stable over the 5 years after discharge from rehabilitation, but generally averaged below normative comparisons. The CIQ Total score was about 1.5 standard deviations below norms reported by Willer and colleagues. 22 Of the three subscales, only the Home Integration subscale showed statistically significant change over time, indicating greater integration in later years. The CHART Total score averaged 79.2 (100 is the expected score for the general population), with only one of its five subscales showing statistically significant change over time. The Occupation scale improved in the 4th and 5th years after discharge from rehabilitation. The most marked discrepancies from norms were evident for the two component scores of the SF-36. Both measures averaged :in the 40s, significantly below expected scores that should approach 100 in a healthy, general population. 19 An explanation for these differences in discrepancies from norms may be partially evident in results of the factor analysis, which showed that both the CHART and, to a lesser degree, the CIQ had component scales that were highly related to functional independence, a factor with which the SF-36 was relatively less associated. Among outcomes that were dynamic over the 5-year period, indices that showed significant improvement were the CIQ Home Integration subscale, the CHART Occupation scale, the Satisfaction With Life Scale, and need for supervision. To illustrate the practical importance of the changes that were observed, figure 1 shows the percentage of persons requiring either direct assistance or supervision over the 5 years after t~ ~= 50 e'- 40 G) z 30 G months years years years years Time Post-discharge Fig 1. Change in need for either direct assistance or supervision J e'- IU months years years years years Time Post-discharge Fig 2. Change in life satisfaction. discharge. Only the need for supervision showed significant change, although a trend for declining need for direct assistance was also evident. Combined, a marked improvement in independence was apparent, increasing from just below 40% in the 6-month to 1-year period to approximately 75% of subjects being independent in the 5th year. As indicated above, some indices appeared to decline before they improved in later years. Figure 2 shows the average SWLS score for subjects over the 5 years after discharge. Figure 3 shows the percentage of subjects gainfully employed or in school in the five time periods. For life satisfaction, early satisfaction declined by the 2nd year after discharge, but then appeared to steadily improve in subsequent time periods. This pattern may be consistent with a "honeymoon period" experienced in the early phase of recovery when the full impact of the consequences of serious brain injury may not be evident to the individual. It is a hopeful finding that life satisfaction may rebound as long-term consequences are accommodated. The percentage of subjects currently in school or gainfully employed also declined in the 1- to 2-year time period, which may be due to both young individuals who complete formal education and subsequently are not able to become employed, as well as those who return to previous employment only to lose the position later. Again, these data are hopeful, in that productivity appears dynamic and may rebound as further adjustments to the effects of injury are made. The only outcome indicator showing decline over the 5-year period was the percentage of individuals abusing substances. While no subjects in their first 2 postdischarge years abused alcohol or used illicit drugs, approximately 25% of those in subsequent time periods appeared to have a substance abuse problem (based on the classification system described earlier). These data are consistent with previous reports, including that of Corrigan and colleagues, H who found that quantities of alcohol consumed by persons with substance abuse problems after brain injury increased dramatically with time postinjury. Kreutzer and colleagues ~ in the Model Systems project re-

7 304 OUTCOMES AFTER TRAUMATIC BRAIN INJURY, Corrigan ~ 4o a. 30 I~ months years years years years Time Post-discharge Fig 3. Change in current productivity. ported increased consumption of alcohol in their sample 2 to 3 years after injury. Kreutzer and colleagues 31 also reported marked increases 2 to 3 years after injury among young adults who incurred traumatic brain injuries. The heuristic value of the current findings may extend to theoretical considerations. Others have argued that subjective well-being is an important dimension of outcome from rehabilitation. 32 The current findings suggest that there may be unique characteristics of life satisfaction, if not affective functioning. The World Health Organization's model of disablement 33 does not address subjective well-being, and this dimension of outcome has generally been ignored in rehabilitation practice. We have tended to make the false assumption that good functional or productive outcome automatically guarantees a positive feeling of subjective well-being. The current study, as well as previous studies of this construct in other populations, are contrary to this notion. 34 Based on an approach proposed by Strupp and Hadley, 35 Corrigan has suggested a tripartite model for conceptualizing outcomes that has as its foundation the assumption that outcome must be judged from at least three perspectives, that of the affected individual, the professional, and the society in general. 36 While outcomes important from one perspective may affect another, one perspective does not determine another. Summarizing outcomes by weighting (explicitly or implicitly) and combining indices from more than one perspective requires a value judgment as to which perspective is more important. Although such value judgments can be made, they deserve careful description, at least, and would be more acceptable if based on consensus among the various constituents of rehabilitation. Too often, quality of life measures are constructed that combine indices from these perspectives without acknowledging the underlying value judgments (eg, a quality of life score composed of several indices of cost of services, a productivity index, and one life satisfaction measure). A tripartite model may be a utilitarian method for conceptualizing outcomes that keeps the question "important to whom" clearly in sight. Several cautions in interpreting the results of this study are worth reiterating. These analyses were exploratory inquiries of data available from research designed for another purpose. Sample sizes in each postdischarge category were small, increasing the potential for problems when generalizing from cross-sectional findings to longitudinal processes. This caution is salient despite the apparent comparability of subgroups in terms of premorbid and injury-related characteristics. A third caution arises from the possibility of systematic bias resulting from the large proportion of subjects lost to follow-up. This bias may be influencing results despite the absence of significant differences between the current sample and the larger population of patients admitted to the Brain Injury Unit. Corrigan and colleagues 12 have reported elsewhere that there is a high incidence of a past history of substance abuse among persons with traumatic brain injury who are lost to research follow-up. Results from the Model Systems suggest that attrition is largest between rehabilitation discharge and 1-year follow-up, with the percentage lost to follow-up declining sharply in subsequent years. 37 In collection of the current data, subjects lost to follow-up were equally distributed across the five time frames with only a slightly greater difficulty finding subjects 4 and 5 years after discharge. Even so, it must be entertained that improvements observed in the later time frames could be due in part to subjects with better adaptation being more likely to be available for research. In summary, this cross-sectional analysis of outcomes over the first 5 years after discharge from inpatient rehabilitation found several indices were dynamic, ie, substance abuse, need for supervision, life satisfaction and selected subscales of the CIQ and CHART. 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