Interpreting Change in Disorders of Consciousness Using the Coma Recovery Scale-Revised

The purpose of this study was to differentiate clinically meaningful improvement or deterioration from normal fluctuations in patients with disorders of consciousness (DoC) following severe brain injury. We computed indices of responsiveness for the Coma Recovery Scale-Revised (CRS-R) using data from a clinical trial of 180 participants with DoC. We used CRS-R scores from baseline (enrollment in a clinical trial) and a 4-week follow-up assessment period for these calculations. To improve precision, we transformed ordinal CRS-R total scores (0-23 points) to equal-interval measures on a 0-100 unit scale using Rasch Measurement theory. Using the 0-100 unit total Rasch measures, we calculated distribution-based 0.5 standard deviation (SD) minimal clinically important difference, minimal detectable change using 95% confidence intervals, and conditional minimal detectable change using 95% confidence intervals. The distribution-based minimal clinically important difference evaluates group-level changes, whereas the minimal detectable change values evaluate individual-level changes. The minimal clinically important difference and minimal detectable change are derived using the overall variability across total measures at baseline and 4 weeks. The conditional minimal detectable change is generated for each possible pair of CRS-R Rasch person measures and accounts for variation in standard error across the scale. We applied these indices to determine the proportions of participants who made a change beyond measurement error within each of the two subgroups, based on treatment arm (amantadine hydrochloride or placebo) or categorization of baseline Rasch person measure to states of consciousness (i.e., unresponsive wakefulness syndrome and minimally conscious state). We compared the proportion of participants in each treatment arm who made a change according to the minimal detectable change and determined whether they also changed to another state of consciousness. CRS-R indices of responsiveness (using the 0-100 transformed scale) were as follows: 0.5SD minimal clinically important difference = 9 units, minimal detectable change = 11 units, and the conditional minimal detectable change ranged from 11 to 42 units. For the amantadine and placebo groups, 70% and 58% of participants showed change beyond measurement error using the minimal detectable change, respectively. For the unresponsive wakefulness syndrome and minimally conscious state groups, 54% and 69% of participants changed beyond measurement error using the minimal detectable change, respectively. Among 115 participants (64% of the total sample) who made a change beyond measurement error, 29 participants (25%) did not change state of consciousness. CRS-R indices of responsiveness can support clinicians and researchers in discerning when behavioral changes in patients with DoC exceed measurement error. Notably, the minimal detectable change can support the detection of patients who make a "true" change within or across states of consciousness. Our findings highlight that the continued use of ordinal scores may result in incorrect inferences about the degree and relevance of a change score.

Randomized Trial of Two Exercise Programs to Increase Physical Activity and Health-Related Quality of Life for Persons With Spinal Cord Injury

Objectives

To compare the effectiveness of two different interventions that promote physical activity in individuals with traumatic spinal cord injury (SCI) and determine the effect of relapse prevention.

Methods

A sequential, multiple assignment, randomized trial was conducted at a universally designed community-based exercise facility. Participants were individuals with traumatic SCI, >3 months post injury, levels C5 to T12, age ≥18 years (N = 79). After randomization, Bridge Program participants completed an 8-week personalized, less intense, exercise program informed by American College of Sports Medicine (ACSM) guidelines and supported with hands-on peer mentoring, exercise of choice, and caregiver training. Structured Exercise participants completed an 8-week program in a group format based on ACSM guidelines. After intervention, participants were randomized to receive or not receive relapse prevention for 6 months. The time and intensity of physical activity and psychological change in depression, anxiety, self-efficacy, and function were assessed with self-reported measures.

Results

Compared to baseline, physical activity increased post intervention for both the Bridge and Structured Exercise programs. Compared to baseline, participants in the Bridge Program recorded fewer anxiety symptoms. No significant changes were noted for either program in depressive symptoms, self-efficacy, or function. There was no difference in relapse prevention between the two groups at 6 months.

Conclusions

The Bridge Program, a novel personalized exercise program with peer support, exercise of choice, and caregiver training, and a structured exercise program both improved self-reported physical activity, but the Bridge Program also reduced anxiety symptoms. This study provides important insight into the limitations of commonly used measures of physical activity and psychosocial domains in people with SCI.

Exploratory examination of the scale structure of the Moorong Self-Efficacy Scale: Application of Rasch Measurement Theory

OBJECTIVE

Exploratory application of the Rasch Measurement (RM) Model for evidence for reproducibility, conceptual/content validity, and structural validity of the Moorong Self-Efficacy Scale (MSES).

STUDY DESIGN

Secondary RM analysis of data collected in a randomized controlled trial comparing two exercise interventions for persons living with spinal cord injury (SCI).

SETTING

Community-dwelling persons living with SCI enrolled in an exercise study.

PARTICIPANTS

Adults (n = 79) enrolled in the parent study had a traumatic SCI > 3 months prior, injury level C5 to T12.

INTERVENTIONS

Not applicable.

OUTCOME MEASURE

The original MSES is a 16-item measure of self-efficacy with a 7-level response scale for un/certainty which was developed for use with persons living with SCI.

RESULTS

We addressed item misfit, infrequent category endorsement, and category step disorder by removing two items and reorganizing the rating scale. Rating scale changes removed category 4 (Neutral), combined categories 1-3 (Very Uncertain, Somewhat Uncertain, and Uncertain) for all items, and further combined certainty categories for two items. Principal components analysis of the residuals indicated a possible second dimension with a first-contrast Eigenvalue of 2.4. However, the contrasted item groups had explained variance <10% and a dis-attenuated correlation = 0.92 indicating they measure the same underlying trait. The small sample size precluded examination of differential item functioning.

CONCLUSIONS

Exploratory RM analysis of MSES produced a 14-item Rasch version which identified structural and content validity evidence concerns inherent in the original MSES. However, results could be biased by a small sample size and further study should examine the item content and rating scale structure with larger, more diverse samples of persons living with SCI.

Comparing indices of responsiveness for the Coma Near-Coma Scale with and without pain items: An Exploratory study

INTRODUCTION

This study aimed to establish the indices of responsiveness for the Coma/Near-Coma (CNC) scale without (8 items) and with (10 items) pain test stimuli. A secondary purpose was to examine whether the CNC 8 items and 10 items differ when detecting change in neurobehavioral function.

METHODS

We analyzed CNC data from three studies of participants with disorders of consciousness: one observational study and two intervention studies. We generated Rasch person measures using the CNC 8 items and CNC 10 items for each participant at two time points 14 ± 2 days apart using Rasch Measurement Theory. We calculated the distribution-based minimal clinically important difference (MCID) and minimal detectable change using 95% confidence intervals (MDC95 ).

RESULTS

We used the Rasch transformed equal-interval scale person measures in logits. For the CNC 8 items: Distribution-based MCID 0.33 SD = 0.41 logits and MDC95  = 1.25 logits. For the CNC 10 items: Distribution-based MCID 0.33 SD = 0.37 logits and MDC95  = 1.03 logits. Twelve and 13 participants made a change beyond measurement error (MDC95 ) using the CNC 8-item and 10-item scales, respectively.

CONCLUSION

Our preliminary evidence supports the clinical and research utility of the CNC 8-item scale for measuring the responsiveness of neurobehavioral function, and that it demonstrates comparable responsiveness to the CNC 10-item scale without administering the two pain items. The distribution-based MCID can be used to evaluate group-level changes while the MDC95 can support clinical, data-driven decisions about an individual patient.

Prognosis of Individual-Level Mobility and Self-Care Stroke Recovery During Inpatient Rehabilitation, Part 1: A Proof-of-Concept Single Group Retrospective Cohort Study

OBJECTIVE

To demonstrate feasibility of generating predictive short-term individual trajectory recovery models after acute stroke by extracting clinical data from an electronic medical record (EMR) system.

DESIGN

Single-group retrospective patient cohort design.

SETTING

Stroke rehabilitation unit at an independent inpatient rehabilitation facility (IRF).

PARTICIPANTS

Cohort of 1408 inpatients with acute ischemic or hemorrhagic stroke with a mean ± SD age of 66 (14.5) years admitted between April 2014 and October 2019 (N=1408).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

0-100 Rasch-scaled Functional Independence Measure (FIM) Mobility and Self-Care subscales.

RESULTS

Unconditional models were best-fit on FIM Mobility and Self-Care subscales by spline fixed-effect functions with knots at weeks 1 and 2, and random effects on the baseline (FIM 0-100 Rasch score at IRF admission), initial rate (slope at time zero), and second knot (change in slope pre-to-post week 2) parameters. The final Mobility multivariable model had intercept associations with Private/Other Insurance, Ischemic Stroke, Serum Albumin, Motricity Index Lower Extremity, and FIM Cognition; and initial slope associations with Ischemic Stroke, Private/Other and Medicaid Insurance, and FIM Cognition. The final Self-Care multivariable model had intercept associations with Private/Other Insurance, Ischemic Stroke, Living with One or More persons, Serum Albumin, and FIM Cognition; and initial slope associations with Ischemic Stroke, Private/Other and Medicaid Insurance, and FIM Cognition. Final models explained 52% and 27% of the variance compared with unconditional Mobility and Self-Care models. However, some EMR data elements had apparent coding errors or missing data, and desired elements from acute care were not available. Also, unbalanced outcome data may have biased trajectories.

CONCLUSIONS

We demonstrate the feasibility of developing individual-level prognostic models from EMR data; however, some data elements were poorly defined, subject to error, or missing for some or all cases. Development of prognostic models from EMR will require improvements in EMR data collection and standardization.

Rasch Reporting Guideline for Rehabilitation Research (RULER): The RULER Statement

The application of Rasch Measurement (RM) Theory to rehabilitation assessments has proliferated in recent years. RM Theory helps design and refine assessments so that items reflect a unidimensional construct, in an equal interval metric that distinguishes among persons of different abilities in a manner that is consistent with the underlying trait. Rapid growth of RM in rehabilitation assessment studies has led to inconsistent results reporting. Clear, consistent, transparent reporting of RM Theory results is important for advancing rehabilitation science and practice based on precise measures. Precise measures, in turn, provide researchers, practitioners, patients, and other stakeholders with tools for effective decision-making. The goal of this Rasch Reporting Guideline for Rehabilitation Research (RULER) is to provide peer-reviewed, evidence-based, transparent, and consistent recommendations for reporting studies that apply RM Theory in a rehabilitation context. The purpose of the guideline is to ensure that authors, reviewers, and editors have uniform expectations about how to write and evaluate research on rehabilitation outcome assessments. A task force of rehabilitation researchers, clinicians, and editors met regularly between November 2018 and August 2020 to identify the need for the guideline, develop an organizing framework, identify content areas, and develop the recommendations. This RULER statement includes the organizing framework and a checklist of 59 recommendations. The guideline is supported by an Explanation & Elaboration manuscript that provides more detail about the framework and recommendations in the checklist. A glossary of key terms and a recommended iterations table are provided in supplemental, online only materials.

Emulating Three Clinical Trials that Compare Stroke Rehabilitation at Inpatient Rehabilitation Facilities to Skilled Nursing Facilities

OBJECTIVE

To inform the design of a potential future randomized controlled trial, we emulated three trials where patient-level outcomes were compared following stroke rehabilitation at Inpatient Rehabilitation Facilities (IRFs) to Skilled Nursing Facilities (SNFs).

DESIGN

Trials were emulated using a 1:1 matched propensity score analysis. The three trials differed as facilities from rehabilitation networks with different case-volumes were compared. Rehabilitation network case-volumes were based on the number of stroke patients that each hospital discharged to each specific IRF or SNF. Trial 1 included 60,529 patients from all networks, trial 2 included 34,444 patients from networks with medium- and large case-volumes (i.e., ≥5 patients), trial 3 included 19,161 patients from networks with large case-volumes (i.e., ≥10 patients). E-values were calculated to estimate the minimum strength that an unmeasured confounder would need to be to nullify the results.

SETTING

A national sample of IRFs and SNFs from across the United States.

PARTICIPANTS

Acute Fee-for-service Medicare stroke patients who received IRF or SNF based rehabilitation.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE(S)

1-year successful community discharge (home for >30 consecutive days) and all-cause mortality.

RESULTS

Overall, 29,500, 15,156, and 7,450 patients were matched for trials 1, 2 and 3. For 1-year successful community discharge, absolute risk differences for IRF patients were 0.21 (95% CI: 0.20, 0.22), 0.17 (95% CI: 0.16, 0.19), and 0.12 (95% CI: 0.10, 0.14) in trials 1, 2 and 3, respectively. For 1-year all-cause mortality, corresponding risk differences were -0.11 (95% CI: -0.12, -0.11), -0.11 (95% CI: -0.12, -0.09), and -0.08 (95% CI: -0.10, -0.06). E-values indicated that a moderately sized unmeasured confounder, with a relative risk of 1.6 to 2.0 would nullify differences in successful community discharge.

CONCLUSION(S)

IRF patients had superior outcomes, but differences were attenuated when IRFs and SNFs from larger rehabilitation networks were compared. The vulnerability of the findings to unmeasured confounding supports the need for an RCT.

Physical Function Recovery Trajectories following Spinal Cord Injury

OBJECTIVE

Explore trajectories of functional recovery that occur during the first two years after spinal cord injury (SCI).

DESIGN

Observational cohort study.

SETTING

Eight SCI Model System sites.

PARTICIPANTS

479 adults with SCI completed four Spinal Cord Injury-Functional Index (SCI-FI) item banks within 4 months of injury and again at 2 weeks, 3, 6, 12, and 24 months following baseline assessment.

INTERVENTION

None.

MAIN OUTCOME MEASURES

SCI-FI Basic Mobility/Capacity (C), Fine Motor Function/C, Self-Care/C, and Wheelchair Mobility/Assistive Technology (AT) item banks.

RESULTS

Growth mixture modeling was used to identify groups with similar trajectory patterns. For the Basic Mobility/C and Wheelchair Mobility/AT domains, models specifying 2 trajectory groups were selected. For both domains, a majority class exhibited average functional levels and gradual improvement, primarily in the first six months. A smaller group of individuals made gradual improvements but had greater initial functional limitations. The Self Care/C domain exhibited a similar pattern; however, a third, small class emerged that exhibited substantial improvement in the first six months. Finally, for individuals with tetraplegia, trajectories of Fine Motor Function/C scores followed two patterns, with individuals reporting generally low initial scores and then making either modest or large improvements. In individual growth curve models, injury/demographic factors predicted initial functional levels but less so with regard to rates of recovery.

CONCLUSIONS

Trajectories of functional recovery followed a small number of change patterns, though variation around these patterns emerged. During the first two years after initial hospitalization, SCI-FI scores showed modest improvements; however, substantial improvements were noted for a small number of individuals with severe limitations in fine motor and self-care function. Future studies should further explore the personal, medical, and environmental characteristics that influence functional trajectories during these first two years and beyond.

Rationale for a Clinical Trial That Compares Acute Stroke Rehabilitation at Inpatient Rehabilitation Facilities to Skilled Nursing Facilities: Challenges and Opportunities

In the United States, approximately 400,000 patients with acute stroke are discharged annually to inpatient rehabilitation facilities (IRFs) or skilled nursing facilities (SNFs). Typically, IRFs provide time-intensive therapy for an average of 2-3 weeks, whereas SNFs provide more moderately intensive therapy for 4-5 weeks. The factors that influence discharge to an IRF or SNF are multifactorial and poorly understood. The complexity of these factors in combination with subjective clinical indications contributes to large variations in the use of IRFs and SNFs. This has significant financial implications for health care expenditure, given that stroke rehabilitation at IRFs costs approximately double that at SNFs. To control health care spending without compromising outcomes, the Institute of Medicine has stated that policy reforms that promote more efficient use of IRFs and SNFs are critically needed. A major barrier to the formulation of such policies is the highly variable and low-quality evidence for the comparative effectiveness of IRF- vs SNF-based stroke rehabilitation. The current evidence is limited by the inability of observational data to control for residual confounding, which contributes to substantial uncertainty around any magnitude of benefit for IRF- vs SNF-based care. Furthermore, it is unclear which specific patients would receive the most benefit from each setting. A randomized controlled trial addresses these issues, because random treatment allocation facilitates an equitable distribution of measured and unmeasured confounders. We discuss several measurement, practical, and ethical issues of a trial and provide our rationale for design suggestions that overcome some of these issues.

Participation by design: Integrating a social ecological approach with universal design to increase participation and add value for consumers

BACKGROUND

Physical activity is an essential component of a healthy lifestyle. Health clubs encourage sustained healthy lifestyles but are still largely not accessible to people with disabilities. Cost is a barrier for accessibility enhancements.

HYPOTHESIS

We postulate that: (A) universal design coupled with a social ecological approach improves measured accessibility compared with existing fitness facilities constructed since the adoption of the ADA; (B) increased accessibility coupled with an environment friendly to people with disabilities attracts more participants to a YMCA than predicted by traditional industry market research producing a recovery of the cost of increased accessibility; and (C) attitudes of facility members toward people with disabilities may improve if an accessible facility facilitates more personal interactions between people with and without disabilities.

METHODS

Accessibility is measured with the Accessibility Instruments Measuring Fitness and Recreation Environments (AIMFREE). Cost recovery is determined by comparing excess membership revenue to the cost of universal design elements beyond regulatory requirements, and attitudes toward people with disabilities are measured with the Attitudes Toward Disabled Persons Scale.

RESULTS

AIMFREE scores were significantly higher than comparison facilities in all areas except for equipment, parking, training, and programs. Excess revenue exceeded the extra cost of accessibility enhancements and attitudes toward people with disabilities did not change.

CONCLUSIONS

Universal design coupled with a social ecological approach improves accessibility in fitness facilities and results in a reasonable payback time. Attitudes toward people with disabilities did not change in a YMCA designed to accommodate people with disabilities.

Safety and feasibility of exoskeleton-assisted walking during acute/sub-acute SCI in an inpatient rehabilitation facility: A single-group preliminary study

Context/objective: Information on the safety and feasibility of lower extremity powered exoskeletons for persons with acute/sub-acute spinal cord injury (SCI) is limited. Understanding the safety and feasibility of employing powered exoskeletons in acute/sub-acute (<6 months post injury) at a SCI acute inpatient rehabilitation (SCI-AIR) facility could guide clinical practice and provide a basis for larger clinical trials on efficacy and effectiveness. Design: Single group observational study. Setting: SCI-AIR. Participants: Participants (n = 12; age: 28-71 years; 58% AIS D; 58% male) with neurological levels of injuries ranging from C2 to L3. Interventions: Up to 90 min of exoskeleton-assisted locomotor training was provided up to three times per week during SCI-AIR. Outcome measures: Safety of device use during inpatient locomotor training was quantified as the number of adverse events (AE) per device exposure hour. Feasibility of device use was defined in terms of protocol compliance, intensity, and proficiency. Results: Concerning safety, symptomatic hypotension was the most common AE reported at 111-events/exoskeleton-hours. Protocol compliance had a mean (SD) of 54% (30%). For intensity, 77% of participants incorporated variable assistance into at least 1 walking session; 70% of participants' sessions were completed with a higher RPE than the physical therapist. In proficiency, 58% achieved at least minimal assistance when walking with the device. Conclusion: Exoskeleton training in SCI-AIR can be safe and feasible for newly injured individuals with SCI who have clinically defined ambulatory goals. Nonetheless, sufficient controls to minimize risks for AEs, such as hypotensive events, are required.

Validation of a pain mechanism classification system (PMCS) in physical therapy practice

The objective of this study was to validate the clinical application of a pain mechanism classification system (PMCS) in clinical practice. We analyzed data abstracted from the medical records of patients who were treated in the outpatient clinics of a large urban rehabilitation hospital in Chicago. We hypothesized that there would be good agreement between the PMCS determined by trained therapists and the PMCS category assigned based on a computer-generated statistical model using patients' signs and symptoms. Using cluster analysis, when we assumed five groups, 97% of patients could be classified. Sensitivity and specificity results with 95% confidence intervals were calculated for the categories using the physical therapist assigned categories (PMCS) as the criterion standard. Sensitivity for four of the five categories (inflammatory, ischemia, peripheral neurogenic, and other ranged from 72·0 to 83·1%). For the central mechanism, sensitivity was much lower at 15%. Specificity for the five categories ranged from 72·4% (ischemia) to 98·8% (central). This study provides empirical support for recent findings in the literature that the peripheral components of a PMCS can be implemented consistently in an outpatient pain clinical practice.

A Multidimensional Rasch Analysis of the Functional Independence Measure Based on the National Institute on Disability, Independent Living, and Rehabilitation Research Traumatic Brain Injury Model Systems National Database

A number of studies have evaluated the psychometric properties of the Functional Independence Measure (FIM™) using Rasch analysis, although none has done so using the National Institute on Disability, Independent Living, and Rehabilitation Research Traumatic Brain Injury Model Systems National Database, a longitudinal database that captures demographic and outcome information on persons with moderate to severe traumatic brain injury across the United States. In the current study, we examine the psychometric properties of the FIM as represented by persons within this database and demonstrate that the FIM comprises three subscales representing cognitive, self-care, and mobility domains. These subscales were analyzed simultaneously using a multivariate Rasch model in combination with a time dependent concurrent calibration scheme with the goal of creating a raw score-to-logit transformation that can be used to improve the accuracy of parametric statistical analyses. The bowel and bladder function items were removed because of misfit with the motor and cognitive items. Some motor items exhibited step disorder, which was addressed by collapsing Categories 1-3 for Toileting, Stairs, Locomotion, Tub/Shower Transfers; Categories 1 and 2 for Toilet and Bed Transfers; and Categories 2 and 3 for Grooming. The strong correlations (r = 0.82-0.96) among the three subscales suggest they should be modeled together. Coefficient alpha of 0.98 indicates high internal consistency. Keyform maps are provided to enhance clinical interpretation and application of study results.

Time and Effort Required by Persons with Spinal Cord Injury to Learn to Use a Powered Exoskeleton for Assisted Walking

BACKGROUND

Powered exoskeletons have been demonstrated as being safe for persons with spinal cord injury (SCI), but little is known about how users learn to manage these devices.

OBJECTIVE

To quantify the time and effort required by persons with SCI to learn to use an exoskeleton for assisted walking.

METHODS

A convenience sample was enrolled to learn to use the first-generation Ekso powered exoskeleton to walk. Participants were given up to 24 weekly sessions of instruction. Data were collected on assistance level, walking distance and speed, heart rate, perceived exertion, and adverse events. Time and effort was quantified by the number of sessions required for participants to stand up, walk for 30 minutes, and sit down, initially with minimal and subsequently with contact guard assistance.

RESULTS

Of 22 enrolled participants, 9 screen-failed, and 7 had complete data. All of these 7 were men; 2 had tetraplegia and 5 had motor-complete injuries. Of these, 5 participants could stand, walk, and sit with contact guard or close supervision assistance, and 2 required minimal to moderate assistance. Walk times ranged from 28 to 94 minutes with average speeds ranging from 0.11 to 0.21 m/s. For all participants, heart rate changes and reported perceived exertion were consistent with light to moderate exercise.

CONCLUSIONS

This study provides preliminary evidence that persons with neurological weakness due to SCI can learn to walk with little or no assistance and light to somewhat hard perceived exertion using a powered exoskeleton. Persons with different severities of injury, including those with motor complete C7 tetraplegia and motor incomplete C4 tetraplegia, may be able to learn to use this device.

Using Rasch motor FIM individual growth curves to inform clinical decisions for persons with paraplegia

STUDY DESIGN

A longitudinal retrospective study.

OBJECTIVE

To better understand individual-level temporal change in functional status for participants with paraplegia in the National Spinal Cord Injury Database (NSCID), as measured by Rasch Transformed Motor Functional Indepedence Measure (FIM) scores.

SETTING

Multicenter/Multistate longitudinal study across the United States.

METHODS

Non-linear random effects modeling, that is, individual growth curve analysis of retrospective data obtained from the National Institute on Disability and Rehabilitation Research (NIDRR) NSCID.

RESULTS

We generated non-linear individual level trajectories of recovery for Rasch Transformed Motor FIM scores that rise rapidly from inpatient rehabilitation admission to a plateau. Trajectories are based on relationships between growth parameters and patient and injury factors: race, gender, level of education at admission, age at injury, neurological level at discharge, American Spinal Injury Association Impairment Scale (AIS) at discharge, days from injury to first system inpatient rehabilitation admission, rehabilitation length of stay, marital status and etiology. On the basis of study results, an interactive tool was developed to represent individual level longitudinal outcomes as trajectories based upon an individual's given baseline characteristics, that is, information supplied by the covariates and provides a robust description of temporal change for those with paraplegia within the NSCID.

CONCLUSIONS

This methodology allows researchers and clinicians to generate and better understand patient-specific trajectories through the use of an automated interactive tool where a nearly countless number of longitudinal paths of recovery can be explored. Projected trajectories holds promise in facilitating planning for inpatient and outpatient services, which could positively impact long term outcomes.

Self-scoring templates for motor and cognitive subscales of the FIM instrument for persons with spinal cord injury

OBJECTIVE

To provide self-scoring templates for the FIM instrument's motor and cognitive scales that enable clinicians to monitor progress during rehabilitation using equal-interval Rasch-calibrated measures instead of ordinal raw scores.

DESIGN

Secondary analysis of a prospective, observational cohort study.

SETTING

Six geographically dispersed hospital-based rehabilitation centers in the United States.

PARTICIPANTS

Subset of consecutively enrolled individuals with new traumatic spinal cord injuries discharged from participating rehabilitation centers (N=1146).

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURES

Subscores of the FIM instrument, including a 13-item motor scale, a 5-item cognitive scale, an 11-item (without sphincter control items) motor scale, a 3-item transfer scale, a 6-item self-care scale, a 3-item self-care upper extremity scale, and a 3-item self-care lower extremity scale.

RESULTS

KeyForms for the FIM instrument scales allow clinicians and investigators to estimate patients' functional status and monitor progress. In cases with no missing data, the look-up tables provide more accurate estimates of patients' functional status.

CONCLUSION

Clinicians can use KeyForms and look-up tables for FIM instrument subscales to monitor patients' progress and communicate improvement in equal-interval units.

An introduction to applying individual growth curve models to evaluate change in rehabilitation: a National Institute on Disability and Rehabilitation Research Traumatic Brain Injury Model Systems report

The abundance of time-dependent information contained in the Spinal Cord Injury and the Traumatic Brain Injury Model Systems National Databases, and the increased prevalence of repeated-measures designs in clinical trials highlight the need for more powerful longitudinal analytic methodologies in rehabilitation research. This article describes the particularly versatile analytic technique of individual growth curve (IGC) analysis. A defining characteristic of IGC analysis is that change in outcome such as functional recovery can be described at both the patient and group levels, such that it is possible to contrast 1 patient with other patients, subgroups of patients, or a group as a whole. Other appealing characteristics of IGC analysis include its flexibility in describing how outcomes progress over time (whether in linear, curvilinear, cyclical, or other fashion), its ability to accommodate covariates at multiple levels of analyses to better describe change, and its ability to accommodate cases with partially missing outcome data. These features make IGC analysis an ideal tool for investigating longitudinal outcome data and to better equip researchers and clinicians to explore a multitude of hypotheses. The goal of this special communication is to familiarize the rehabilitation community with IGC analysis and encourage the use of this sophisticated research tool to better understand temporal change in outcomes.

Are components of a comprehensive medical assessment predictive of work disability after an episode of occupational low back trouble?

STUDY DESIGN

One hundred fifty-nine subacute low back work-injured patients completed a full medical assessment at baseline. A full repeat examination was performed 3 months later, when return-to-work status was determined.

OBJECTIVE

To determine the prognostic value of a comprehensive medical assessment for the prediction of return-to-work status.

SUMMARY OF BACKGROUND DATA

A systematic review of the work disability prediction literature of low back trouble prognosis revealed that no high-quality studies included a full medical history and physical examination in the design. The results of studies included in the systematic review were equivocal with respect to predictive usefulness of medical variables.

METHODS

Participants completed medical history questionnaires and then were clinically examined by one of six experienced examiners (three physicians and three physiotherapists). Return-to-work status was measured 3 months later, and predictive validity was evaluated using logistic regression modeling.

RESULTS

Medical variables (, medical history subscales, physical examination subscales, and lumbar range-of-motion tests) showed modest correct classification rates varying between 61.6% and 69.1% for participants.

CONCLUSIONS

Comprehensive medical assessments play a crucial role in the early identification of serious pathology after low back trouble. We were unable to identify, however, any medical evaluation variables that would account for significant proportions of variance in return to work. The weight of evidence obtained in this study suggests that injured workers' subjective interpretations and appraisals may be more powerful predictors of the course of postinjury recovery than exclusively medical assessments.

Reliability of the lumbar flexion, lumbar extension, and passive straight leg raise test in normal populations embedded within a complete physical examination

STUDY DESIGN

The study measured the reliability of the passive straight leg raise (SLR) test and lumbar range of motion (LROM) tests measured as continuous variables embedded within a comprehensive physical examination.

OBJECTIVES

To determine the reliability of the SLR and LROM test scores when they are measured with a Cybex electronic inclinometer (Lumex, Inc., New York, NY) within a physical examination.

SUMMARY OF BACKGROUND DATA

Good published empirical reliability exists for the Cybex and for SLR and LROM tests when the measurements are taken in isolation from other physical examination procedures. Reliability of the Cybex for continuous SLR and LROM measurement within a physical examination has not been assessed, however.

METHODS

Forty-five participants were seen by one of two physician/physiotherapist teams. Participants were examined by both team members. The first examiner conducted the first tests and retested 1 week later (intrarater reliability). The second examined the participants the day after their first appointment (inter-rater reliability).

RESULTS

Only two scores showed substantial reliability (defined as r > or = 0.60). These scores were left (r = 0.81) and right (r = 0.79) SLR intrarater reliability. All other scores fell below the specified cutoff.

CONCLUSIONS

SLR and LROM scores used clinically are collected during comprehensive physical examinations. Most scores gathered under these conditions were not reliable. These findings have implications for the use of clinically derived SLR and LROM scores.

Commentary on the American Medical Association guides' lumbar impairment validity checks

STUDY DESIGN

The American Medical Association's (AMA) Guides to the Evaluation of Permanent Impairment range of motion-based (ROM) lumbar impairment model validity checks were reviewed. Published literature of lumbar ROM (LROM) testing also was reviewed for application of the AMA validity checking protocols.

OBJECTIVE

The utility and feasibility of use of the AMA Guides' ROM lumbar impairment ratings were examined.

SUMMARY OF BACKGROUND DATA

Although they appear to be essential components of the ROM model, few published studies report use of these validity checks. Of at least 22 reviewed studies of LROM testing, only six studies included at least three measurements (the bare minimum) of LROM. Furthermore, only two (9.1%) reported performance of the LROM validity check. Only one, however, reported the results.

METHODS

English language journals were searched on Medline using "region, lumbar," "range of motion," "validity of results," "observer variation," and "low back pain" as title and subject search terms. The study methodologies approximating the AMA Guides' specifications were included in the analysis.

RESULTS

Under normal conditions of ROM measurement, 33% of three consecutive lumbar flexion and 27% of three consecutive lumbar extension measurements failed the LROM validity check. In addition, across three different experimental sessions (each with more than three consecutive LROM measurements taken) only 15 participants (33%) had valid flexion scores and only 24 participants (53%) had valid extension scores across all three sessions.

CONCLUSION

Technical complications inherent in the ROM-based impairment-rating model render the validity checks difficult to perform satisfactorily and thus rarely used.

Analysis of the convergent and discriminant validity of published lumbar flexion, extension, and lateral flexion scores

STUDY DESIGN

Articles reflecting the convergent or discriminant validity of the lumbar range of motion tests were reviewed and compared. Mean scores and standard deviations for lumber range of motion from healthy control subjects were plotted against those from patients with low back injuries.

OBJECTIVE

To use published research to analyze the convergent and discriminant validity of lumbar range of motion tests for the characterization of low back pain and injury.

SUMMARY OF BACKGROUND DATA

Several publications have addressed lumbar range of motion validity. Individual studies suggest that the tests possess convergent validity, but that their discriminant validity is indeterminate.

METHODS

English-language journals were searched on Medline using "region," "lumbar," "range of motion," "validity of results," "observer variation," and "low back pain" as title and subject search terms. The study methods approximating the specifications of the American Medical Association Guides to the Evaluation of Permanent Impairment were included in the analysis.

RESULTS

Convergent validity research showed inconsistent relations between inclinometric and radiographic lumbar range of motion measurements. Some studies showed strong relation, whereas others showed essentially no relation between the two techniques. Correlations between lumbar range of motion scores and spinal disability and function were similarly inconclusive. Studies reporting mean scores and standard deviations for lumbar range of motion measurements showed a high degree of overlap between the scores of participants with low back injuries and those without such injuries.

CONCLUSIONS

Convergent and discriminant validities of the lumbar range of motion tests currently require further substantiation. Absolute lumbar range of motion scores may not be suitable as the sole determinants of low back pathology diagnosis. Implications for using the lumbar range of motion tests to characterize low back injuries in medicolegal situations are discussed.