Flora M. Hammond

Assessment Scales for Disorders of Consciousness: Evidence-Based Recommendations for Clinical Practice and Research

OBJECTIVES To conduct a systematic review of behavioral assessment scales for disorders of consciousness (DOC); provide evidence-based recommendations for clinical use based on their content validity, reliability, diagnostic validity, and ability to predict functional outcomes; and provide research recommendations on DOC scale development and validation. DATA SOURCES Articles published through March 31, 2009, using MEDLINE, CINAHL, Psychology and Behavioral Sciences Collection, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Cochrane Central Register of Controlled Trials, Biomedical Reference Collection, and PsycINFO. Thirteen primary terms that defined DOC were paired with 30 secondary terms that defined aspects of measurement. Scale names, abbreviations, and authors were also used as search terms. Task force members identified additional articles by using personal knowledge and examination of references in reviewed articles. STUDY SELECTION Primary criteria included the following: (1) provided reliability, diagnostic validity, and/or prognostic validity data; (2) examined a cohort, case control, or case series sample of persons with DOC who were age older than or equal to 18 years; and (3) assessed in an acute care or rehabilitation setting. Articles were excluded if peer review was not conducted, original data were not reported, or an English language article was not available. The initial search yielded 580 articles. After paired rater review of study abstracts, guideline development was based on 37 articles representing 13 DOC scales. DATA EXTRACTION Rater pairs classified studies addressing diagnostic and prognostic validity by using the American Academy of Neurology 4-tier level of evidence scheme, and reliability by using a task force-developed 3-tier evidence scheme. An independent quality review of ratings was conducted, and corrections were made. DATA SYNTHESIS The Coma Recovery Scale-Revised (CRS-R), Sensory Stimulation Assessment Measure (SSAM), Wessex Head Injury Matrix (WHIM), Western Neuro Sensory Stimulation Profile (WNSSP), Sensory Modality Assessment Technique (SMART), Disorders of Consciousness Scale (DOCS), and Coma/Near-Coma Scale (CNC) have acceptable standardized administration and scoring procedures. The CRS-R has excellent content validity and is the only scale to address all Aspen Workgroup criteria. The SMART, SSAM, WHIM, and WNSSP demonstrate good content validity, containing items that could distinguish persons who are in a vegetative state, are in a minimally conscious state (MCS), or have emerged from MCS. The Full Outline of UnResponsiveness Score (FOUR), WNSSP, CRS-R, Comprehensive Levels of Consciousness Scale (CLOCS), and Innsbruck Coma Scale (INNS) showed substantial evidence of internal consistency. The FOUR and the CRS-R showed substantial evidence of good interrater reliability. Evidence of diagnostic validity and prognostic validity in brain injury survivor samples had very high levels of potential bias because of methodologic issues such as lack of rater masking. CONCLUSIONS The CRS-R may be used to assess DOC with minor reservations, and the SMART, WNSSP, SSAM, WHIM, and DOCS may be used to assess DOC with moderate reservations. The CNC may be used to assess DOC with major reservations. The FOUR, INNS, Glasgow-Liege Coma Scale, Swedish Reaction Level Scale-1985, Loewenstein Communication Scale, and CLOCS are not recommended at this time for bedside behavioral assessment of DOC because of a lack of content validity, lack of standardization, and/or unproven reliability.

Relationship between Glasgow coma scale and functional outcome.

The Glasgow Coma Scale (GCS) is routinely used in the acute care setting after traumatic brain injury (TBI) to guide decisions in triage, based on its ability to predict morbidity and mortality. Although the GCS has been previously demonstrated to predict mortality, efficacy in prediction of functional outcome has not been established. The purpose of this study was to assess the value of the acute GCS in predicting functional outcome in survivors of TBI. This study used the Multicenter National Institute on Disability and Rehabilitation Research TBI Model Systems database of 501 patients who had received acute medical care and inpatient rehabilitation within a coordinated neurotrauma program for treatment of TBI. Initial and lowest 24 hr GCS scores were correlated with the following outcome measures: the Disability Rating Scale (DRS), Rancho Los Amigos Levels of Cognitive Functioning Scale (LCFS), and cognitive and motor components of the Functional Independence Measure (FIM(SM)-COG and FIM(SM)-M). Outcome data were collected at admission to and discharge from the inpatient TBI rehabilitation unit. Correlation analysis revealed only modest, but statistically significant, relationships between initial and lowest GCS scores and outcome variables. Initial and lowest GCS score comparison with outcome demonstrated the following correlation coefficients: admission DRS, -0.25 and -0.28; discharge DRS, -0.24 and -0.24; admission LCFS, 0.31 and 0.33; discharge LCFS, 0.27 and 0.25; admission FIM-COG, 0.36 and 0.37; discharge FIM-COG, 0.23 and 0.23; admission FIM-M, 0.31 and 0.31; discharge FIM-M, 0.25 and 0.21. The GCS as a single variable may have limited value as a predictor of functional outcome.

Mortality Over Four Decades After Traumatic Brain Injury Rehabilitation: A Retrospective Cohort Study

OBJECTIVE To investigate mortality, life expectancy, risk factors for death, and causes of death in persons with traumatic brain injury (TBI). DESIGN Retrospective cohort study. SETTING Used data from an inpatient rehabilitation facility, the Social Security Death Index, death certificates, and the U.S. population age-race-sex-specific and cause-specific mortality rates. PARTICIPANTS Persons with TBI (N=1678) surviving to their first anniversary of injury admitted to rehabilitation from an acute care hospital within 1 year of injury between 1961 and 2002. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Vital status, standardized mortality ratio, life expectancy, cause of death. RESULTS Persons with TBI were 1.5 times more likely to die than persons in the general population of similar age, sex, and race, resulting in an estimated average life expectancy reduction of 4 years. Within the TBI population, the strongest independent risk factors for death after 1 year postinjury were being older, being male, having less education, having a longer hospitalization, having an earlier year of injury, and being in a vegetative state at rehabilitation discharge. After 1 year postinjury, persons with TBI were 49 times more likely to die of aspiration pneumonia, 22 times more likely to die of seizures, 4 times more likely to die of pneumonia, 3 times more likely to commit suicide, and 2.5 times more likely to die of digestive conditions than persons in the general population of similar age, sex, and race. CONCLUSIONS This study demonstrated life expectancy after TBI rehabilitation is reduced and associated with specific risk factors and causes of death.

Impact of Age on Long-Term Recovery From Traumatic Brain Injury

OBJECTIVE To determine whether older persons are at increased risk for progressive functional decline after traumatic brain injury (TBI). DESIGN Longitudinal cohort study. SETTING Traumatic Brain Injury Model Systems (TBIMS) rehabilitation centers. PARTICIPANTS Subjects enrolled in the TBIMS national dataset. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Disability Rating Scale (DRS), FIM instrument cognitive items, and the Glasgow Outcome Scale-Extended. RESULTS Participants were separated into 3 age tertiles: youngest (16-26y), intermediate (27-39y), and oldest (> or =40y). DRS scores were comparable across age groups at admission to a rehabilitation center. The oldest group was slightly more disabled at discharge from rehabilitation despite having less severe acute injury severity than the younger groups. Although DRS scores for the 2 younger groups improved significantly from year 1 to year 5, the greatest magnitude of improvement in disability was seen among the youngest group. In addition, after dividing patients into groups according to whether their DRS scores improved (13%), declined (10%), or remained stable (77%) over time, the likelihood of decline was found to be greater for the 2 older groups than for the youngest group. A multiple regression model showed that age has a significant negative influence on DRS score 5 years post-TBI after accounting for the effects of covariates. CONCLUSIONS This study supported our primary hypothesis that older patients show greater decline over the first 5 years after TBI than younger patients. In addition, the greatest amount of improvement in disability was observed among the youngest group of survivors. These results suggest that TBI survivors, especially older patients, may be candidates for neuroprotective therapies after TBI.

Traumatic Brain Injury as a Chronic Health Condition

Growing evidence indicates that multiple types of brain injury, including traumatic brain injury, are dynamic conditions that continue to change years after onset. For a subset of individuals who incur these injuries, decline occurs over time and is likely due to progressive neurodegenerative processes, comorbid conditions, aging, behavioral choices, and/or psychosocial factors. Deterioration, whether directly or indirectly associated with the original brain injury, necessitates a clinical approach as a chronic health condition, including identification of risk and protective factors, protocols for early identification, evidence-based preventive and ameliorative treatment, and training in self-management. We propose that the acknowledgment of chronic brain injury will facilitate the research necessary to provide a disease management approach.

Longitudinal outcome of patients with disordered consciousness in the NIDRR TBI model systems programs

Few studies address the course of recovery from prolonged disorders of consciousness (DOC) after severe traumatic brain injury (TBI). This study examined acute and long-term outcomes of persons with DOC admitted to acute inpatient rehabilitation within the National Institute on Disability and Rehabilitation Research (NIDRR) TBI Model Systems Programs (TBIMS). Of 9028 persons enrolled from 1988 to 2009, 396 from 20 centers met study criteria. Participants were primarily male (73%), Caucasian (67%), injured in motor vehicle collision (66%), with a median age of 28, and emergency department Glasgow Coma Scale (GCS) score of 3. Participant status was evaluated at acute rehabilitation admission and discharge and at 1, 2, and 5 years post-injury. During inpatient rehabilitation, 268 of 396 (68%) regained consciousness and 91 (23%) emerged from post-traumatic amnesia (PTA). Participants demonstrated significant improvements on GCS (z=16.135, p≤0.001) and Functional Independence Measure (FIM) (z=15.584, p≤0.001) from rehabilitation admission (median GCS=9; FIM=18) to discharge (median GCS=14; FIM=43). Of 337 with at least one follow-up visit, 28 (8%) had died by 2.1 years (mean) after discharge. Among survivors, 66 (21%) improved to become capable of living without in-house supervision, and 63 demonstrated employment potential using the Disability Rating Scale (DRS). Participants with follow-up data at 1, 2, and 5 years post-injury (n=108) demonstrated significant improvement across all follow-up evaluations on the FIM Cognitive and Supervision Rating Scale (p<0.01). Significant improvements were observed on the DRS and FIM Motor at 1 and 2 years post-injury (p<0.01). Persons with DOC at the time of admission to inpatient rehabilitation showed functional improvement throughout early recovery and in years post-injury.

Change and predictors of change in communication, cognition, and social function between 1 and 5 years after traumatic brain injury.

Objective:To study cognitive, communication, and social changes experienced by individuals between 1 and 5 years after traumatic brain injury (TBI). Design:Prospective cohort. Setting and Participants:TBI Model System Database with 927 eligible subjects using a cohort with complete 1- and 5-year data (N = 292). Main Outcome Measures:Change in Functional Independence Measure™-Cognitive (FIM-Cog) items from Year 1 to Year 5 postinjury. Results:On the FIM-Cog Total score, 26% individuals improved, 61% stayed the same, and 14% worsened by more than 1 point from Year 1 to Year 5. On the 2 FIM Communication items, 19% individuals improved, 68% stayed the same, and 13% worsened by greater than 1 point. On the FIM Social Interaction item, 12% individuals improved, 76% stayed the same, and 11% worsened. On the FIM Memory and Problem Solving items, 34% individuals improved, 48% stayed the same, and 19% worsened. Several variables predicted this improvement and worsening, some of which were available at the time of injury and most were those available at 1 year postinjury. The Memory and Problem Solving items, taken together, showed fewer participants at ceiling at Year 1 and more change between Year 1 and Year 5 compared to the Communication and Social Interaction items. Conclusions:Many individuals did not demonstrate meaningful change on FIM-Cog and its component items from Year 1 to Year 5. In particular, a high proportion of improvement was observed in Memory/Problem Solving, and worsening in Social Interaction. Demographic and functional indicators present at 1 year postinjury may be predictive of subsequent change.

Causes of death following 1 year postinjury among individuals with traumatic brain injury.

ObjectiveTo investigate causes of death in individuals with traumatic brain injury (TBI). DesignRetrospective cohort study. SettingUtilized data from the TBI Model Systems National Database, the Social Security Death Index, death certificates, and the US population age-race-gender-cause-specific mortality rates for 1994. PatientsTwo thousand one hundred forty individuals with TBI completing inpatient rehabilitation in 1 of 15 National Institute on Disability and Rehabilitation Research-funded TBI Model Systems of Care between 1988 and 2001, and surviving past 1 year postinjury. Main Outcome MeasuresPrimary cause of death based on the International Classification of Diseases - 9th Revision - Clinical Modification - coded death certificates. ResultsIndividuals with TBI were about 37 times more likely to die of seizures, 12 times more likely to die of septicemia, 4 times more likely to die of pneumonia, and about 3 times more likely to die of other respiratory conditions (excluding pneumonia), digestive conditions, and all external causes of injury/poisoning than were individuals in the general population of similar age, gender, and race. ConclusionLong-term follow-up of individuals with TBI should increase vigilance for, and prevention of, diagnoses frequently causing death (circulatory disorders) and diagnoses with a high relative risk of causing death in this population (seizures, septicemia, respiratory and digestive conditions, and external causes of injury).

Use of injury severity variables in determining disability and community integration after traumatic brain injury.

BACKGROUND Long-term outcome is important in managing traumatic brain injury (TBI), an epidemic in the United States. Many injury severity variables have been shown to predict major morbidity and mortality. Less is known about their relationship with specific long-term outcomes. METHODS Glasgow Coma Scale, Revised Trauma Score, Injury Severity Score, and Trauma and Injury Severity Score, along with other demographic and premorbid values, were obtained for 378 consecutive patients hospitalized after TBI at a Level I trauma center between September 1997 and May 1998. Of this cohort, 120 patients were contacted for 1-year follow-up assessment with the Disability Rating Scale, Community Integration Questionnaire, and employment data. RESULTS Univariate analyses showed these to be significant single predictors of 1-year outcome. Multivariate analyses revealed that the Revised Trauma Score and Glasgow Coma Scale had significant additive value in predicting injury variables Disability Rating Scale scores when combined with other demographic and premorbid variables studied. Predictive models of 1-year outcome were developed. CONCLUSION Injury severity variables are significant single outcome predictors and, in combination with premorbid and demographic variables, help predict long-term disability and community integration for individuals hospitalized with TBI.

Gender and traumatic brain injury: Do the sexes fare differently?

Objective: To examine the relationship between gender and cognitive recovery 1 year following traumatic brain injury (TBI). Methods: Patients with blunt TBI were identified from the TBI Model Systems of Care National Database, multi-centre cohort study. The included patients (n = 325) were 16–45 years at injury, admitted to an acute care facility within 24 hours, received inpatient rehabilitation, had documented admission Glasgow Coma Scale (GCS) scores, completed neuropsychological follow-up 1 year post-injury and did not report pre-morbid learning problems. Multivariate analyses of variance examined the unadjusted association between gender and six cognitive domains examining attention/working memory, verbal memory, language, visual analytic skills, problem-solving and motor functioning. Analyses of covariance models were constructed to determine if confounding factors biased the observed associations. Results: Females performed significantly better than males on tests of attention/working memory and language. Males outperformed females in visual analytic skills. Gender remained significantly associated with performance in these areas when controlling for confounding variables. Conclusions: These results suggest a better cognitive recovery of females than males following TBI. However, future studies need to include non-TBI patients to control for possible pre-injury gender-related differences, as well as to conduct extended follow-ups to determine the stability of the observed differences.