Jacob Kean

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.

Formal Distinctiveness of High- and Low-Imageability Nouns: Analyses and Theoretical Implications

Words associated with perceptually salient, highly imageable concepts are learned earlier in life, more accurately recalled, and more rapidly named than abstract words (R. W. Brown, 1976; Walker & Hulme, 1999). Theories accounting for this concreteness effect have focused exclusively on semantic properties of word referents. A novel possibility is that word structure may also contribute to the effect. We report a corpus-based analysis of the phonological and morphological structures of a large set of nouns with imageability ratings (N = 2,023). High- and low-imageability nouns differed by length, etymology, prosody, affixation, phonological neighborhood density, and rates of consonant clustering. On average, nouns denoting abstract concepts were longer, more derivationally complex, and emerged in English from a different distribution of languages than did concrete nouns. We address implications for interactivity of word form and meaning as pertain to theories of word concreteness, lexical acquisition, and word processing.

Delirium detection in clinical practice and research: Critique of current tools and suggestions for future development

Delirium is underrecognized clinically. Many tools have been developed to assist with the diagnosis of delirium, and they vary greatly in purpose, quality, and administration time. It is suggested that future development of delirium assessment instruments be guided by a dichotomization of raters into expert and nonexpert groups. Careful consideration of the needs of the two groups suggests that assessment instruments designed for nonexperts should be entirely objective, whereas those instruments developed for experts should include the full range of constructs associated with the syndrome. This conceptualization is explored in detail, and existing assessment instruments are considered briefly in light of this position.

Three Core Domains of Delirium Validated Using Exploratory and Confirmatory Factor Analyses

OBJECTIVE To confirm the existence of the proposed three-core symptom domains in delirium by analyzing a dataset of nondemented adults using selected core symptoms as measured by the Delirium Rating Scale-Revised-98 (DRS-R98) scale. METHODS Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) of proposed delirium core symptoms were conducted in a pooled international dataset of 592 delirious and nondelirious patients using DSM-IV criteria from 14 studies with comparable methodologies. Using DRS-R98 categorization, 445 had either subsyndromal or full delirium and comprised the delirium group. The dataset was divided into three independent random subsamples to perform a stepwise analysis. First we performed EFA in 100 cases to delineate latent factor loadings of DRS-R98 items selected to represent the three-core domains (circadian, higher level thinking, and cognitive). These items were then assessed using CFA-modeling (n = 246) followed by a CFA-validation (n = 246). Reliability and goodness of fit of these two CFA were assessed statistically. RESULTS DRS-R98 items representing the proposed delirium core symptoms loaded onto one factor in the EFA, supporting their core nature. The two CFA confirmed the nature of this core factor as comprising three core domains where DRS-R98 items each loaded with high values (>0.7) onto their corresponding core domain (circadian, higher level thinking, and cognitive) with good fit and reliability. Attention was DRS-R98 item with the highest loading in CFA, followed by thought process, and then by sleep-wake cycle and motor behavior. CONCLUSIONS Our EFA and CFA confirm and validate the proposed three-core domains of delirium, where symptoms were highly related to the domain that they were hypothesized to represent. These domains are consistent with delirium being a state of impaired consciousness, and should be considered necessary to assess whether in clinical or research settings.

Fatigue and Pain: Relationships with Physical Performance and Patient Beliefs after Stroke

Abstract Background: Fatigue and pain are common after stroke, potentially impacting stroke recovery. Objective: This study examines the frequency and impact of fatigue and pain in people with chronic stroke. Method: Seventy-seven people with chronic stroke completed a one-time assessment consisting of a battery of self-report and performance tools to describe and quantify mobility issues post stroke. We assessed the proportion of individuals with fatigue and pain and the relationship between fatigue and pain and other variables including gait (10-meter walk and 6-minute walk test), balance (Berg Balance Scale), activity and participation (ICF Measure of Participation and Activities), chronic disease self-efficacy (Chronic Disease Self-Efficacy Scale), and balance self-efficacy (Activity-Specific Balance Confidence Scale). Additionally, subgroup comparisons were made between participants with and without coexisting fatigue and pain. Results: Fatigue and pain were reported by 66% and 45% of study participants, respectively. Thirty-four percent of the sample reported co-existing fatigue and pain. Participants with coexisting fatigue and pain demonstrated significantly lower chronic disease and balance self-efficacy and decreased activity than participants without coexisting fatigue and pain. Individually, fatigue correlated with balance, chronic disease self-efficacy, balance self-efficacy, activity, and participation, whereas pain correlated with chronic disease self-efficacy, balance self-efficacy, and activity. Conclusion: Fatigue and pain are common after stroke and are negatively correlated with outcomes important to rehabilitation. Efforts focused on examining the impact of interventions on fatigue and pain are warranted. It is possible that changes to these body structure limitations could positively impact functional recovery and community re-entry after stroke.

Phenotype of subsyndromal delirium using pooled multicultural Delirium Rating Scale—Revised-98 data

OBJECTIVE There is no consensus definition for the phenotype of subsyndromal delirium (SSD), a subthreshold state to full delirium. Without an a priori definition we applied advanced analytic techniques to discern SSD. METHOD We pooled Delirium Rating Scale-Revised-98 (DRS-R98) data from 859 DSM-IV diagnosed nondemented delirious adults and nondelirious controls collected by investigators in 7 countries. Discriminant analyses defined an SSD group that was then compared to Nondelirium and Delirium groups. RESULTS SSD (n=138) had intermediate DRS-R98 item severities between Delirium (n=497) and Nondelirium (n=224) groups, where groups significantly differed on all DRS-R98 items (ANOVA p<.001) except delusions. Discriminant analysis found SSD phenomenologically closer to Delirium than Nondelirium. Using full multinomial logistical regression, SSD was distinguished from Nondelirium by temporal onset, sleep-wake cycle, perceptual disturbances, motor retardation, delusion, affective lability, and all cognitive items; SSD was similar to Delirium in thought process, language, motor agitation or retardation, sleep-wake cycle, all cognitive items, fluctuation and physical disorder. The multivariate model correctly classified 94.2% of Nondelirium, 75.4% of SSD and 97.2% of Delirium subjects. Binary logistic regression of six core domain symptoms (sleep-wake cycle, thought process, language, attention, orientation, and visuospatial ability) together were found as highly differentiating of SSD from Nondelirium, which correctly classified almost 80% of SDD. CONCLUSIONS SSD is intermediate in severity between nondelirious controls and full syndromal delirium, but its phenotype is more like delirium. Core domain delirium symptoms present at milder severity in SSD should be evaluated further for utility in detecting and managing SSD, preventing delirium, and possible inclusion in DSM-V.

Rasch Measurement Analysis of the Mayo-Portland Adaptability Inventory (MPAI-4) in a Community-Based Rehabilitation Sample

The precise measurement of patient outcomes depends upon clearly articulated constructs and refined clinical assessment instruments that work equally well for all subgroups within a population. This is a challenging task in those with acquired brain injury (ABI) because of the marked heterogeneity of the disorder and subsequent outcomes. Although essential, the iterative process of instrument refinement is often neglected. This present study was undertaken to examine validity, reliability, dimensionality and item estimate invariance of the Mayo-Portland Adaptability Inventory - 4 (MPAI-4), an outcome measure for persons with ABI. The sampled population included 603 persons with traumatic ABI participating in a home- and community-based rehabilitation program. Results indicated that the MPAI-4 is a valid, reliable measure of outcome following traumatic ABI, which measures a broad but unitary core construct of outcome after ABI. Further, the MPAI-4 is composed of items that are unbiased toward selected subgroups except where differences could be expected [e.g., more chronic traumatic brain injury (TBI) patients are better able to negotiate demands of transportation than more acute TBI patients]. We address the trade-offs between strict unidimensionality and clinical applicability in measuring outcome, and illustrate the advantages and disadvantages of applying single-parameter measurement models to broad constructs.

Operating Characteristics of PROMIS Four-Item Depression and Anxiety Scales in Primary Care Patients with Chronic Pain

OBJECTIVE Depression and anxiety are prevalent in patients with chronic pain and adversely affect pain, quality of life, and treatment response. The purpose of this psychometric study was to determine the reliability and validity of the four-item Patient Reported Outcomes Measurement Information System (PROMIS) depression and anxiety scales in patients with chronic pain. DESIGN Secondary analysis of data from the Stepped Care to Optimize Pain care Effectiveness study, a randomized clinical trial of optimized analgesic therapy. SETTING Five primary care clinics at the Roudebush VA Medical Center (RVAMC) in Indianapolis, Indiana. SUBJECTS Two hundred forty-four primary care patients with chronic musculoskeletal pain. METHODS All patients completed the four-item depression and anxiety scales from the PROMIS 29-item profile, as well as several other validated psychological measures. The minimally important difference (MID) using the standard error of measurement (SEM) was calculated for each scale, and convergent validity was assessed by interscale correlations at baseline and 3 months. Operating characteristics of the PROMIS measures for detecting patients who had probable major depression or were anxiety-disorder screen-positive were calculated. RESULTS The PROMIS scales had good internal reliability, and the MID (as represented by two SEMs) was 2 points for the depression scale and 2.5 points for the anxiety scale. Convergent validity was supported by strong interscale correlations. The optimal screening cutpoint on the 4- to 20-point PROMIS scales appeared to be 8 for both the depression and anxiety scales. CONCLUSIONS The PROMIS four-item depression and anxiety scales are reasonable options as ultra-brief measures for screening in patients with chronic pain.

Initial validation of a brief provisional diagnostic scale for delirium

Primary objective: The Delirium Diagnostic Tool–Provisional (DDT-Pro) is a newly developed provisional diagnostic tool for delirium presented here. This study evaluated its accuracy and validity in a population of participants with acquired brain injury (ABI). Research design: Cross-sectional study. Methods: Thirty-six patients with ABI, including traumatic brain injury (TBI; n = 29) and intraparenchymal haemorrhage (ICH; n = 7) were assessed at admission to inpatient rehabilitation using the DDT-Pro, the Delirium Rating Scale–Revised 98 (DRS-R98) and DSM-IV-TR diagnostic criteria for delirium. Results: Using receiver operating characteristic (ROC) analysis, the estimate of accuracy, the area under the curve (AUC), was 0.994, and the DDT-Pro accurately classified 35/36 (97%) observations vs the DSM-IV-TR gold standard. The DDT-Pro correlated well with the DRS-R98 both in terms of raw score (r = −0.913, p < 0.0001) and estimates of the duration of delirium (r = 0.975, p < 0.0001). Conclusions: The DDT-Pro is supported as a measure of delirium following ABI. Further validation in ABI and other medical populations is recommended.

Arbitrary Symbolism in Natural Language Revisited: When Word Forms Carry Meaning

Cognitive science has a rich history of interest in the ways that languages represent abstract and concrete concepts (e.g., idea vs. dog). Until recently, this focus has centered largely on aspects of word meaning and semantic representation. However, recent corpora analyses have demonstrated that abstract and concrete words are also marked by phonological, orthographic, and morphological differences. These regularities in sound-meaning correspondence potentially allow listeners to infer certain aspects of semantics directly from word form. We investigated this relationship between form and meaning in a series of four experiments. In Experiments 1–2 we examined the role of metalinguistic knowledge in semantic decision by asking participants to make semantic judgments for aurally presented nonwords selectively varied by specific acoustic and phonetic parameters. Participants consistently associated increased word length and diminished wordlikeness with abstract concepts. In Experiment 3, participants completed a semantic decision task (i.e., abstract or concrete) for real words varied by length and concreteness. Participants were more likely to misclassify longer, inflected words (e.g., “apartment”) as abstract and shorter uninflected abstract words (e.g., “fate”) as concrete. In Experiment 4, we used a multiple regression to predict trial level naming data from a large corpus of nouns which revealed significant interaction effects between concreteness and word form. Together these results provide converging evidence for the hypothesis that listeners map sound to meaning through a non-arbitrary process using prior knowledge about statistical regularities in the surface forms of words.