Further validation of the Preference-Based Stroke Index three months after stroke.

OBJECTIVE: To estimate the construct validity of the Preference-Based Stroke Index and its value added over a generic measure, the EuroQol-5D-3L at three months after stroke. DESIGN: This is a secondary analysis of an existing inception cohort. Pearson correlation coefficients were estimated to test construct validity and Generalized Estimating Equation analysis was conducted to compare the strength of the correlations of the Preference-Based Stroke Index and EuroQol-5D-3L with other measures. SETTING: Community. SUBJECTS: Participants (n = 488) with confirmed diagnosis of stroke hospitalized within 72 hours. MAIN MEASURES: Health-related quality of life was measured using Preference-Based Stroke Index and EuroQol-5D-3L. For validation purposes, the Stroke Impact Scale, Short Form-36 V1, Walking Speed, Two-Minute Walk Test, Berg Balance Scale, and the Mini-Mental State Examination were used. The Barthel Index and Canadian Neurological Scale were used to define known groups. RESULTS: Preference-Based Stroke Index correlated moderately with the EuroQol-5D-3L (r = 0.73), Walking Speed (r = 0.68), Two-Minute Walk Test (r = 0.73), and Berg Balance Scale (r = 0.70) and strongly with Stroke Impact Scale Activities of Daily Living (r = 0.80). Correlations were significantly higher for the Preference-Based Stroke Index than EuroQol-5D-3L. Participants with mild stroke had a higher mean Preference-Based Stroke Index score (77.9 ± 20.6) than participants with severe stroke (62.8 ± 20.3). Participants with functional independence had higher Preference-Based Stroke Index (85.7 ± 11.9) than those dependent for activities of daily living (60.8 ± 19.7). CONCLUSION: Preference-Based Stroke Index demonstrated significantly higher construct validity compared to the EuroQol-5D-3L at three months post stroke and can discriminate among known groups.

Properties of a brief assessment tool for longitudinal measurement of cognition in people living with HIV.

BACKGROUND: Mild cognitive impairment is common in chronic HIV infection and there is concern that it may worsen with age. Distinguishing static impairment from on-going decline is clinically important, but the field lacks well-validated cognitive measures sensitive to decline and feasible for routine clinical use. Measures capable of detecting improvement are also needed to assess interventions. The objective of this study is to estimate the extent of change on repeat administration of three different forms of a brief computerized cognitive assessment battery (B-CAM) developed for assessing cognitive ability in the mildly-impaired to normal range in people living with HIV. We hypothesized no change over a six-month period in people on effective antiretroviral therapy. METHODS: 102 HIV+ individuals completed a set of computerized cognitive tasks on three occasions over a six-month period. Rasch analysis was used to determine if change over time (i.e. improvement due to practice) was uniform across tasks and to refine scoring in order to produce three forms of the B-CAM of equivalent level of difficulty. Group-based trajectory analysis (GBTA) was then applied to determine if performance at baseline influenced the magnitude of practice-related improvement on the battery as a whole over the course of follow-up. RESULTS: Two cognitive tasks (fluency and word recall) had different levels of difficulty across test sessions, related to the different forms of the tasks. These two items were split by testing session. For all other items, the level of difficulty remained constant across all three time points. GBTA showed that the sample was composed of three distinct groups of people with unique trajectories, defined mainly by level of cognitive ability at baseline. Only the highest group showed an apparent improvement over time, but this change fell within measurement error. CONCLUSIONS: Rasch analysis provides mathematical confirmation that these three forms of the B-CAM are of equivalent difficulty. GBTA demonstrates that no adjustment of the total score is required to correct for practice effects. Application of these modern statistical methods paves the way towards rapid and robust quantification of change in cognition.

Toward a Meaningful Definition of Recovery After Hip Fracture: Comparing Two Definitions for Community-Dwelling Older Adults.

OBJECTIVES: To examine the course of recovery and resulting health-related quality of life (HRQL) after low-trauma hip fracture using 2 different definitions of recovery. DESIGN: Inception cohort with 8 assessments over 1 year. SETTING: Participants were recruited from a tertiary-care hospital and followed up in the community. PARTICIPANTS: Community-dwelling hip fracture patients (N=47, 75% of all eligible; aged ≥65y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Prefracture functional level was used to identify subgroups of participants with similar trajectories of mobility over time. Recovery in functional mobility was defined in 2 ways: the "traditional" definition (return to prefracture level of functional mobility) and a "targeted recovery" definition (ability to climb 10 steps). Both were measured using the Lower Extremity Functional Scale. HRQL was measured using the RAND 36-Item Short-Form Health Survey. RESULTS: Participants were categorized into 3 subgroups with: low, medium, and high prefracture functional abilities. Agreement between the 2 definitions of recovery (quantified using κ coefficient) was strong for the medium group (.81; 95% confidence interval, .56-1.00), weak for the high group (.46; 95% confidence interval, 0.0-.99), and minimal for the low group (.12; 95% confidence interval, 0.0-.328). Contrary to the traditional definition, patients who achieved targeted recovery had statistically and clinically better HRQL than the rest of the cohort throughout the study (estimated average difference of 10.8 points on RAND 36-Item Short-Form Health Survey; 95% confidence interval, 6.67-15.07). CONCLUSIONS: The agreement between the 2 definitions of recovery ranged from minimal to strong according to patient group. Using a functional target to define recovery predicted HRQL better. It is vital to consider the definition of recovery carefully for research or clinical practice because it can influence subsequent decisions (eg, endorsing a specific intervention or discharging patients).

How have research questions and methods used in clinical trials published in Clinical Rehabilitation changed over the last 30 years?

Research in rehabilitation has grown from a rare phenomenon to a mature science and clinical trials are now common. The purpose of this study is to estimate the extent to which questions posed and methods applied in clinical trials published in Clinical Rehabilitation have evolved over three decades with respect to accepted standards of scientific rigour. Studies were identified by journal, database, and hand searching for the years 1986 to 2016.A total of 390 articles whose titles suggested a clinical trial of an intervention, with or without randomization to form groups, were reviewed. Questions often still focused on methods to be used (57%) rather than what knowledge was to be gained. Less than half (43%) of the studies delineated between primary and secondary outcomes; multiple outcomes were common; and sample sizes were relatively small (mean 83, range 5 to 3312). Blinding of assessors was common (72%); blinding of study subjects was rare (19%). In less than one-third of studies was intention-to-treat analysis done correctly; power was reported in 43%. There is evidence of publication bias as 83% of studies reported either a between-group or a within-group effect. Over time, there was an increase in the use of parameter estimation rather than hypothesis testing and there was evidence that methodological rigour improved.Rehabilitation trialists are answering important questions about their interventions. Outcomes need to be more patient-centred and a measurement framework needs to be explicit. More advanced statistical methods are needed as interventions are complex. Suggestions for moving forward over the next decades are given.

Quantifying cognition at the bedside: a novel approach combining cognitive symptoms and signs in HIV.

BACKGROUND: Up to half of all people with HIV infection have some degree of cognitive impairment. This impairment is typically mild, but nonetheless often disabling. Although early detection of cognitive impairment offers the greatest hope of effective intervention, there are important barriers to this goal in most clinical settings. These include uncertainty about how self-reported cognitive symptoms relate to objective impairments, and the paucity of bedside measurement tools suitable for mild deficits. Clinicians need guidance in interpreting cognitive symptoms in this population, and a brief cognitive measurement tool targeted to mild impairment. We addressed these two problems together here. The objective of this study was to determine the extent to which performance on cognitive tests and self-reported cognitive symptoms form a unidimensional construct. METHODS: Two hundred three HIV+ individuals completed the Montreal Cognitive Assessment, computerized cognitive tasks and a questionnaire eliciting cognitive symptoms. Rasch measurement theory was applied to determine whether patient-reported and performance items could be combined to measure cognition as a unidimensional latent construct. RESULTS: Performance-based items and cognitive symptoms are arranged hierarchically along the same continuum of cognitive ability, forming a measure with thresholds covering a broad spectrum of ability that has good internal reliability. The cognitive symptoms that fit the measurement model relate to important aspects of everyday life, providing evidence that the identified construct is meaningful. CONCLUSIONS: This finding lays the foundation for a rapid measure of cognitive ability in people with HIV infection that is feasible for routine clinical use, and shows that some cognitive symptoms are systematically related to performance in this population.

Using existing data to identify candidate items for a health state classification system in multiple sclerosis.

PURPOSE: In multiple sclerosis (MS), the use of preference-based measures is limited to generic measures such as Health Utilities Index Mark 2 and 3, the EQ-5D and the SF-6D. However, the challenge of using such generic preference-based measures in people with MS is that they may not capture all domains of health relevant to the disease. Therefore, the main aim of this paper is to describe the development of a health state classification system for MS patients. The specific objectives are: (1) to identify items best reflecting the domains of quality of life important to people with MS and (2) to provide evidence for the discriminative capacity of the response options by cross-walking onto a visual analog scale of health rating. METHODS: The data come from an epidemiologically sampled population of people with MS diagnosed post-1994. The dataset consisted of 206 items relating to impairments, activity limitations, participation restrictions, health perception and quality of life. Important domains were identified from the responses to the Patient Generated Index, an individualized measure of quality of life. The extent to which the items formed a uni-dimensional, linear construct was estimated using Rasch analysis, and the best item was selected using the threshold map. RESULTS: The sample was young (mean age 43) and predominantly female (n = 140/189; 74%). The P-PBMSI classification system consisted of five items, with three response levels per item, producing a total of 243 possible health states. Regression coefficient values consistently decreased between response levels and the linear test for trend were statistically significant for all items. The linear test for trend indicated that for each item the response options provided the same discriminative ability within the magnitude of their capacity. A scoring algorithm was estimated using a simple additive formula. The classification system demonstrated convergent validity against other measures of similar constructs and known-groups validity between different clinical subgroups. CONCLUSION: This study produced a health state classifier system based on items impacted upon by MS, and demonstrated the potential to discriminate the health impact of the disease.

Necessary and sufficient causes of participation post-stroke: practical and philosophical perspectives.

INTRODUCTION: Participation, a construct within the disability/functioning framework, is evaluated on a person's involvement in life situations including family, community, work, social, and civic life. In the context of recovering from a major health event, participation is a treatment goal and it is known to correlate with the quality of life. OBJECTIVE: The purpose of this study is to track the dynamics of participation post-stroke in relationship to the dynamics of walking capacity, social support, and mood. METHODS: An inception cohort was followed over the first post-stroke year. Group-based trajectory analysis, a form of latent class analysis, was used to identify distinctive groups of individuals with similar trajectories. Dual trajectories were used to estimate concordance between participation trajectory and trajectories for each of the three constructs under study. RESULTS: From the sample of 102 persons (mean age 70), four trajectories of participation were identified, two of which were qualified as excellent and very good, and two qualified as fair and poor. All those with excellent walking showed excellent participation. However, people with excellent (and very good) community participation had a range of walking capacities. Most (82%) people with normal mood showed excellent participation. People with good mood but not meeting norms for age showed the complete range of participation trajectories from excellent to poor. The higher proportion of people with excellent or good social support (57%) showed excellent participation. CONCLUSION: Two treatable component causes of participation, walking capacity and mood, were identified; of these, only excellent walking capacity could be considered a sufficient cause.

Nordic walking for geriatric rehabilitation: a randomized pilot trial.

PURPOSE: There is a need to identify effective interventions to promote walking capacity in seniors. This study compares nordic walking (NW) and usual overground walking (OW) and estimates the relative efficacy in improving walking capacity (endurance and gait speed) of the elderly. METHOD: Single blind, site-stratified, randomized, pilot trial designed to estimate the amount of change with NW and OW. Main outcomes were distance walked measured by 6-min walk test (6MWT) and comfortable gait speed measured by 5-meter walk test (5MWT). Explanatory variables were age, sex, number of comorbidities, walking aids, balance, pain, and leg function. RESULTS: NW and OW participants improved, respectively, 45 and 41 m on 6MWT and increased their gait speed by 0.14 and 0.07 m/s, respectively. NW effect sizes were moderate for 6MWT (ES = 0.53) and large for gait speed (effect size (ES) = 0.68). OW demonstrated moderate effect size for 6MWT (ES = 0.53) but a small one for gait speed (ES = 0.33). Relative efficacy, which was obtained from the ratio of NW and OW effects' sizes, was 1 for 6MWT and 2.06 for gait speed. CONCLUSIONS: NW is 106% more effective in improving gait speed among elderly than OW.

Development and initial psychometric evaluation of the Stroke Arm Ladder: a measure of upper extremity function post stroke.

OBJECTIVE: To develop an adaptive measure, the Stroke Arm Ladder, to parsimoniously quantify upper extremity function post stroke. SETTING: Various studies conducted in Montreal and elsewhere in Canada. SUBJECTS: A total of 4058 persons with stroke who participated in various studies were assessed on different occasions post stroke. Assessments spanned from 3 days to 1 year post stroke. MAIN MEASURES: A calibrated bank containing 49 items from tests and indices designed to assess global motor recovery of the upper extremity, upper extremity function and activities involving the upper extremity was used. Data including all testing occasions were analysed to test whether they adhered to the expectations of the Rasch partial credit model and whether item hierarchy remained stable across testing occasions. RESULTS: Fifteen items did not meet the requirements of the Rasch model and were deleted. An adaptive measure of upper extremity function, the Stroke Arm Ladder, containing 34 items was created. The easiest item was partially executing the bilateral task of tying a scarf around one's neck, while the hardest item was being able to transfer more than 60 blocks on the Box and Block Test. The items' difficulty thresholds cover a wide range of difficulty levels from -7.4 to 6.2 and the global fit statistics (χ(2): 331; probability: 0.18), confirmed content validity. CONCLUSION: The Stroke Arm Ladder demonstrates adequate initial psychometric properties. Further testing of the measure in its adaptive format is necessary before it can be used clinically.

Relationship between muscle strength and functional walking capacity among people with stroke.

The purpose of this study was to estimate, using the Position-Specific Global Index (PSGI) of Lower-Limb Muscle Strength, the extent to which muscle strength is independently associated with functional walking capacity. We performed an observational, cross-sectional study with 63 patients poststroke (onset between 3 and 12 months) at a major teaching hospital in an urban Canadian city. We assessed functional walking capacity with the six-minute walk test (6MWT) and muscle strength with handheld dynamometry. We established the relationship between the lower-limb muscles and functional walking capacity with the PSGI. The PSGI explained 70% (p < 0.001) of the variability in the 6MWT, whereas the index of alternate against-gravity muscle strength explained 39% and the hip flexors in a supine position explained 51%.

The extent to which common health-related quality of life indices capture constructs beyond symptoms and function.

PURPOSE: This study proposes to identify for 5 widely used generic HRQL and QOL measures the extent to which function and global feelings of well-being are represented in their content. METHODS: The 5 indices were the EQ-5D, the HUI, the SF-36, SF-12, and the WHOQOL-Bref. A total of 15 raters with a variety of health and research backgrounds mapped the items. Raters independently identified all codes that could possibly map to the item and indicated the code that best reflected the underlying intent of the item, using the standardized mapping rules and methodology. A Delphi process aided consensus for each of the items. The consensus rounds involved reconsideration of item codes for which 70% of raters did not agree on the "best" code. These consensus rounds were terminated when item codes reached the threshold of 70% agreement or when it became evident from that consensus would not be reached. RESULTS: Function was a predominant construct for the 5 indices, with the proportion of items capturing function ranging from a low of 27% for the WHOQOL-Bref to a high of 92% for the SF-12. Less than 50% of items within the indices mapped to the granularity of function as described by the ICF. CONCLUSIONS: This paper demonstrates an additional method to validate the content of health-related indices to supplement the qualitative methods of consulting with experts and patients.

Preliminary evidence for the development of a stroke specific geriatric depression scale.

UNLABELLED: Measuring depression among persons with stroke faces many challenges; diagnostic tools are lengthy and do not measure the extent of depression; screening tools are not stroke-specific; and metrics from the available indices do not provide a value that is mathematically or clinically meaningful. PURPOSE: To provide evidence for the development of a stroke specific Geriatric Depression Scale screening measure (SS-GDS) through Rasch methodology. METHODS: Secondary analyses of a randomized controlled trial post-stroke. Interviews from 91 subjects aged 71 (SD 10) over three time points or 240 interviews were analyzed. Rasch Analysis helped transform the 30-item GDS onto a logit scale. Unidimensionality, item fit, redundancy, and differential item functioning (DIF) were assessed. RESULTS: Seventeen items fit the model to form a hierarchical measure ranging in difficulty from +1.2 to -1.8 logits. Preliminary psychometric properties of reliability, validity, and responsiveness were adequate. Two items that demonstrated DIF, one for language and one for gender, were split. CONCLUSION: The 17-item SS-GDS Rasch measure was developed to screen for post-stroke depression (PSD) and provide an important step toward quantifying PSD. If revalidated in a larger sample, the SS-GDS could provide a mathematically valid index to screen for depression in stroke survivors.

The disutility of restenosis--the impact of repeat percutaneous coronary intervention on quality of life.

BACKGROUND: Percutaneous coronary intervention (PCI) with coronary stenting is a common medical procedure that is used to treat the symptoms of both stable angina and acute coronary syndromes. Drugeluting stents (DES) decrease restenosis and repeat revascularization procedures but are more expensive than bare-metal stents. A proper cost-effectiveness analysis of DES requires an understanding of the health value patients place on the avoidance of restenosis accompanied by a repeat PCI. OBJECTIVE: To estimate quality-of-life (QoL) benefits ascribed to avoiding the return of coronary symptoms and the need for a repeat revascularization procedure. METHODS: A prospective, single-centre study was conducted involving PCI patients. A time trade-off (TTO) question, based on a hypothetical restricted lifespan of 10 years, was used to estimate the QoL benefits patients attach to the avoidance of recurrent symptoms and a repeat PCI. This was accomplished by interviewing the patients by telephone, two weeks post-PCI. The TTO question was also administered to the catheterization laboratory staff. RESULTS: Between January and March 2007, and between April and June 2008, 103 interviews were completed. The median TTO was zero weeks (interquartile range zero to 1.7 weeks). Six interventional cardiologists and eight cardiac catheterization nurses reported a similar median disutility. CONCLUSION: Despite acknowledgement of the substantial clinical benefits of DES, the results of the present study suggest that patients do not place a great disutility on avoiding restenosis, thereby providing little QoL justification for the large incremental cost associated with this technology.

Development and initial psychometric evaluation of an item bank created to measure upper extremity function in persons with stroke.

OBJECTIVE: To create and illustrate the development of a method to parsimoniously and hierarchically assess upper extremity function in persons after stroke. DESIGN: Data were analyzed using Rasch analysis. SETTING: Re-analysis of data from 8 studies involving persons after stroke. SUBJECTS: Over 4000 patients with stroke who participated in various studies in Montreal and elsewhere in Canada. METHODS: Data comprised 17 tests or indices of upper extremity function and health-related quality of life, for a total of 99 items related to upper extremity function. Tests and indices included, among others, the Box and Block Test, the Nine-Hole Peg Test and the Stroke Impact Scale. Data were collected at various times post-stroke from 3 days to 1 year. RESULTS: Once the data fit the model, a bank of items measuring upper extremity function with persons and items organized hierarchically by difficulty and ability in log units was produced. CONCLUSION: This bank forms the basis for eventual computer adaptive testing. The calibration of the items should be tested further psychometrically, as should the interpretation of the metric arising from using the item calibration to measure the upper extremity of individuals.

A measure of physical functioning to define stroke recovery at 3 months: preliminary results.

OBJECTIVE: To develop a physical functioning measure through Rasch analysis conceptualized using the International Classification of Functioning, Disability and Health (ICF). DESIGN: Observational cohort study. SETTING: Acute-hospital and community-based study. PARTICIPANTS: Subjects (N=235) hospitalized with postacute stroke and reassessed in the community at 3-months (mean age, 71.6+/-12.9 y). INTERVENTIONS: None. MAIN OUTCOME MEASURES: Functional assessments 3 months poststroke included self-report and observational indices and tests commonly used to evaluate stroke survivors. Sociodemographic information was also collected. Rasch analysis assisted in combining the items across ICF components to develop the measure. Items were retained based on fit to the model and relationship to the construct; reliability and validity were assessed. RESULTS: The best 44 items formed the Physical Functioning Measure at 3 months (F3m) measure of functioning evaluating limb movement, balance, activities of daily living, and participation. All Rasch model assumptions were met. Both item and person reliably (.96) indicated a stable hierarchy, while precision varied from .51 to 1.2 logits. Early evidence for construct validity is adequate. CONCLUSIONS: The F3m combines patient reported and observed ratings of performance items into a single measure quantifying functioning with good preliminary psychometric properties that with further testing can assist in directing and evaluating interventions and recovery.

Measuring cognition in a geriatric outpatient clinic: Rasch analysis of the Montreal Cognitive Assessment.

OBJECTIVE: To evaluate the psychometric properties of the Montreal Cognitive Assessment as a quantitative measure of cognitive ability. DATA ANALYZED: A total of 222 cases extracted from a clinical database (57-91 years) of patients screened for cognitive impairment in outpatient geriatric assessment clinics. DATA COLLECTED: Demographic information and individual item responses to Montreal Cognitive Assessment. RESULTS: Comparison of the data with a unidimensional Rasch model indicated that the total score obtained by summing across all items yields a reliable (0.75) quantitative estimate of global cognitive ability. All items fit the model and together spanned a range of difficulty from -3.75 to +2.88 logits. Items were assessed for differential item functioning across such patient characteristics as age, education, and language spoken. We provide a table for converting Montreal Cognitive Assessment total scores onto a linearly scaled score, with guidelines for interpreting changes in Montreal Cognitive Assessment score in terms of their statistical significance. CONCLUSIONS: The Montreal Cognitive Assessment can provide a reliable and valid quantitative estimate of cognitive ability in a geriatric cognitive disorders clinic setting.

A measure of early physical functioning (EPF) post-stroke.

OBJECTIVE: To develop a comprehensive measure of Early Physical Functioning (EPF) post-stroke quantified through Rasch analysis and conceptualized using the International Classification of Functioning Disability and Health (ICF). DESIGN: An observational cohort study. SUBJECTS: A cohort of 262 subjects (mean age 71.6 (standard deviation 12.5) years) hospitalized post-acute stroke. METHODS: Functional assessments were made within 3 days of stroke with items from valid and reliable indices commonly utilized to evaluate stroke survivors. Information on important variables was also collected. Principal component and Rasch analysis confirmed the factor structure, and dimensionality of the measure. Rasch analysis combined items across ICF components to develop the measure. Items were deleted iteratively, those retained fit the model and were related to the construct; reliability and validity were assessed. RESULTS: A 38-item unidimensional measure of the EPF met all Rasch model requirements. The item difficulty matched the person ability (mean person measure: -0.31; standard error 0.37 logits), reliability of the person-item-hierarchy was excellent at 0.97. Initial validity was adequate. CONCLUSION: The 38-item EPF measure was developed. It expands the range of assessment post acute stroke; it covers a broad spectrum of difficulty with good initial psychometric properties that, once revalidated, can assist in planning and evaluating early interventions.

Validation of the Charlson Comorbidity Index for predicting functional outcome of stroke.

OBJECTIVE: To determine whether a separate comorbidity index is needed to predict functional outcome after stroke, we compared the predictability of the Charlson Comorbidity Index (CMI) and the Functional Comorbidity Index (FCI) to that of a stroke-specific comorbidity index with function quantified with a measure developed with a Rasch model as outcome. DESIGN: Two prospective inception cohort studies, in 1996 through 1998 and in 2002 through 2005, with up to 9 months of follow-up. SETTING: Participants enrolled in 2 studies were recruited from acute care hospitals in the Montreal area. PARTICIPANTS: For study one, 1027 persons with a first stroke discharged into the community were eligible; the 437 who were interviewed a second time at 6 months were included in the analysis. In study two, 235 of 262 patients with stroke were enrolled. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: To predict recovery, we developed 3 stroke-specific comorbidity algorithms based on the estimated strength of association between comorbidities and stroke function. The various indices were compared on the basis of their predictive ability with a c statistic. RESULTS: In study 1, the c statistics were .758, .763, .766, and .763 for the stroke-specific algorithms 1, 2, and 3 and the CMI, respectively. In study 2, the c statistics were .680, .700, .704, .714, and .714 for the algorithms 1, 2, and 3, the CMI, and the FCI, respectively. CONCLUSIONS: For purposes of case-mix adjustment, the CMI seems to be more than adequate.

Development of a measure of functioning for stroke recovery: the functional recovery measure.

PURPOSE: To develop a parsimonious measure of functioning for persons after stroke. METHOD: A sub-set of 206 community-dwelling subjects with a first stroke from a larger cohort was interviewed within 9 months using 39 items from five indices assessing functioning. Information was collected on influencing variables: age, stroke type and severity, and previous health. Two statistical methods, factor analysis and Rasch analysis, confirmed the item structure, hierarchy and dimensionality of the measure. Statistics confirmed fit to the model; internal consistency was also assessed. Items were deleted iteratively based on fit and relationship to the construct. RESULTS: The subjects were predominately male (63%) aged on average 68-years-old. A 12-item unidimensional functioning measure was developed. All items and persons fit the Rasch model with stable item-person reliability indices of 0.98 and 0.91, respectively. Item precision (standard errors) ranged from 0.14-0.37 logits. Gaps in measurement occurred at the extremes of the measure and there was a small ceiling effect. CONCLUSIONS: A 12-item measure captured the concept of functioning that could be used as a prototype to quantify recovery post-stroke. These items could form the basis for a measure of functioning.

Incorporating the International Classification of Functioning, Disability, and Health (ICF) into an electronic health record to create indicators of function: proof of concept using the SF-12.

OBJECTIVE: The purpose of this proof-of-concept study was to assess the feasibility of using a generic health measure to create coded functional status indicators and compare the characterization of a stroke population using coded functional indicators and using health-related quality-of-life summary measures alone. DESIGN: Multiple raters assigned International Classification of Functioning, Disability, and Health (ICF) codes to the items of the 12-Item Short Form Health Survey (SF-12). Data for comparing the information from the SF-12 and from ICF codes were derived from the Montreal Stroke Cohort Study that was set up to examine the long-term impact of stroke. Available for analysis were data from 604 persons with stroke, average age 69 years, and 488 controls, average age 62 years. MEASUREMENT: The SF-12 provides two summary scores, one for physical health and one for mental health. Domains of the ICF are coded to three digits, before the decimal; specific categorizations of impairments, activity limitations, and participation restrictions are coded to four digits before the decimal. RESULTS: Persons with stroke scored, on average, approximately 10 points lower than controls on physical and mental health. The ICF coding indicated that this was attributed, not surprisingly, to greater difficulty in doing moderate activities including housework, climbing stairs, and working and was not attributed to differences in pain. Differences in mental health were attributed most strongly to greater fatigue (impairment in energy), but all areas of mental health were affected to some degree. CONCLUSION: The ICF coding provided enhanced functional status information in a format compatible with the structure of administrative health databases.