Psychometric Evaluation of the Improved Work-Disability Functional Assessment Battery.

OBJECTIVE: To assess psychometric properties of the improved Work Disability Functional Assessment Battery (WD-FAB 2.0). DESIGN: Longitudinal study. SETTING: Community. PARTICIPANTS: Three samples of working-age (21-66) adults (N=1006): (1) unable to work because of a physical condition (n=375); (2) unable to work because of a mental health condition (n=296); (3) general United States working age sample (n=335). INTERVENTION: NA. MAIN OUTCOME MEASURES: All samples completed the WD-FAB 2.0; the second administration came 5 days after the first. Construct validity was examined by convergent and divergent correlational analysis using legacy measures. Test-retest reliability was assessed by intraclass correlation coefficients (ICC3,1). Standard error of the mean (SEM) and minimal detectable change (MDC90) were calculated to measure scale precision and sensitivity. RESULTS: Physical function ICCs ranged from 0.69 to 0.77 in the general sample, and 0.66 to 0.86 in the disability sample. Mental health function scales ICCs ranged from 0.62 to 0.73 in the general sample, and 0.74 to 0.76 in the disability sample. SEMs for all scales indicated good discrimination; those for the physical function scales were generally lower than those for the mental health scales. MDC90 values ranged from 3.41 to 10.55. Correlations between all WD-FAB 2.0 scales and legacy measures were in the expected direction. CONCLUSIONS: The study provides substantial support for the reliability and construct validity of the WD-FAB 2.0 among 3 diverse samples. Although initially developed for use within the Social Security Administration (SSA), these results suggest that the WD-FAB 2.0 could be used for assessment and measurement of work-related physical and mental health function in other contexts as well.

Broadening horizons: the case for capturing function and the role of health informatics in its use.

BACKGROUND: Human activity and the interaction between health conditions and activity is a critical part of understanding the overall function of individuals. The World Health Organization's International Classification of Functioning, Disability and Health (ICF) models function as all aspects of an individual's interaction with the world, including organismal concepts such as individual body structures, functions, and pathologies, as well as the outcomes of the individual's interaction with their environment, referred to as activity and participation. Function, particularly activity and participation outcomes, is an important indicator of health at both the level of an individual and the population level, as it is highly correlated with quality of life and a critical component of identifying resource needs. Since it reflects the cumulative impact of health conditions on individuals and is not disease specific, its use as a health indicator helps to address major barriers to holistic, patient-centered care that result from multiple, and often competing, disease specific interventions. While the need for better information on function has been widely endorsed, this has not translated into its routine incorporation into modern health systems. PURPOSE: We present the importance of capturing information on activity as a core component of modern health systems and identify specific steps and analytic methods that can be used to make it more available to utilize in improving patient care. We identify challenges in the use of activity and participation information, such as a lack of consistent documentation and diversity of data specificity and representation across providers, health systems, and national surveys. We describe how activity and participation information can be more effectively captured, and how health informatics methodologies, including natural language processing (NLP), can enable automatically locating, extracting, and organizing this information on a large scale, supporting standardization and utilization with minimal additional provider burden. We examine the analytic requirements and potential challenges of capturing this information with informatics, and describe how data-driven techniques can combine with common standards and documentation practices to make activity and participation information standardized and accessible for improving patient care. RECOMMENDATIONS: We recommend four specific actions to improve the capture and analysis of activity and participation information throughout the continuum of care: (1) make activity and participation annotation standards and datasets available to the broader research community; (2) define common research problems in automatically processing activity and participation information; (3) develop robust, machine-readable ontologies for function that describe the components of activity and participation information and their relationships; and (4) establish standards for how and when to document activity and participation status during clinical encounters. We further provide specific short-term goals to make significant progress in each of these areas within a reasonable time frame.

Improving Assessment of Work Related Mental Health Function Using the Work Disability Functional Assessment Battery (WD-FAB).

Purpose To improve the mental health component of the Work Disability Functional Assessment Battery (WD-FAB), developed for the US Social Security Administration's (SSA) disability determination process. Specifically our goal was to expand the WD-FAB scales of mood & emotions, resilience, social interactions, and behavioral control to improve the depth and breadth of the current scales and expand the content coverage to include aspects of cognition & communication function. Methods Data were collected from a random, stratified sample of 1695 claimants applying for the SSA work disability benefits, and a general population sample of 2025 working age adults. 169 new items were developed to replenish the WD-FAB scales and analyzed using factor analysis and item response theory (IRT) analysis to construct unidimensional scales. We conducted computer adaptive test (CAT) simulations to examine the psychometric properties of the WD-FAB. Results Analyses supported the inclusion of four mental health subdomains: Cognition & Communication (68 items), Self-Regulation (34 items), Resilience & Sociability (29 items) and Mood & Emotions (34 items). All scales yielded acceptable psychometric properties. Conclusions IRT methods were effective in expanding the WD-FAB to assess mental health function. The WD-FAB has the potential to enhance work disability assessment both within the context of the SSA disability programs as well as other clinical and vocational rehabilitation settings.

Improving measures of work-related physical functioning.

PURPOSE: To expand content of the physical function domain of the Work Disability Functional Assessment Battery (WD-FAB), developed for the US Social Security Administration's (SSA) disability determination process. METHODS: Newly developed questions were administered to 3532 recent SSA applicants for work disability benefits and 2025 US adults. Factor analyses and item response theory (IRT) methods were used to calibrate and link the new items to the existing WD-FAB, and computer-adaptive test simulations were conducted. RESULTS: Factor and IRT analyses supported integration of 44 new items into three existing WD-FAB scales and the addition of a new 11-item scale (Community Mobility). The final physical function domain consisting of: Basic Mobility (56 items), Upper Body Function (34 items), Fine Motor Function (45 items), and Community Mobility (11 items) demonstrated acceptable psychometric properties. CONCLUSIONS: The WD-FAB offers an important tool for enhancement of work disability determination. The FAB could provide relevant information about work-related functioning for initial assessment of claimants; identifying denied applicants who may benefit from interventions to improve work and health outcomes; enhancing periodic review of work disability beneficiaries; and assessing outcomes for policies, programs and services targeting people with work disability.

Work disability functional assessment battery: feasibility and psychometric properties.

OBJECTIVE: To assess the feasibility and psychometric properties of 8 scales covering 2 domains of the newly developed Work Disability Functional Assessment Battery (WD-FAB): physical function (PF) and behavioral health (BH) function. DESIGN: Cross-sectional study. SETTING: Community. PARTICIPANTS: Adults (N=973) unable to work because of a physical (n=497) or a mental (n=476) disability. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Each disability group responded to a survey consisting of the relevant WD-FAB scales and existing measures of established validity. The WD-FAB scales were evaluated with regard to data quality (score distribution, percentage of "I don't know" responses), efficiency of administration (number of items required to achieve reliability criterion, time required to complete the scale) by computerized adaptive testing (CAT), and measurement accuracy as tested by person fit. Construct validity was assessed by examining both convergent and discriminant correlations between the WD-FAB scales and scores on same-domain and cross-domain established measures. RESULTS: Data quality was good, and CAT efficiency was high across both WD-FAB domains. Measurement accuracy was very good for PF scales; BH scales demonstrated more variability. Construct validity correlations, both convergent and divergent, between all WD-FAB scales and established measures were in the expected direction and range of magnitude. CONCLUSIONS: The data quality, CAT efficiency, person fit, and construct validity of the WD-FAB scales were well supported and suggest that the WD-FAB could be used to assess PF and BH function related to work disability. Variation in scale performance suggests the need for future work on item replenishment and refinement, particularly with regard to the Self-Efficacy scale.

Difference, disparity, and disability: a comparison of health, insurance coverage, and health service use on the basis of race/ethnicity among US adults with disabilities, 2006-2008.

BACKGROUND: In the United States, research on health disparities has begun to include people with disabilities as a minority population. However, there is a gap in our knowledge of whether, and to what extent, racial and ethnic disparities may affect the health or health care access of people with disabilities. OBJECTIVES: We examined potential disparities in overall health, insurance coverage status, and health service use between non-Hispanic whites, non-Hispanic blacks, and Hispanics, among a nationally representative US sample of adults with and without disabilities (N=63,257), using both bivariate and multivariate methods. We tested 2 definitions of disparity. RESULTS: Under the more conservative definition, we confirmed the presence of both racial and ethnic disparities in overall health, total annual health care visits, and the percentage reporting no doctor visit during the year among people with less severe disabilities; Hispanics also evidenced a disparity in rates uninsured relative to non-Hispanic whites in this group. Racial/ethnic disparities were less common among persons with more severe disabilities that affected activities of daily living or instrumental activities. CONCLUSIONS: We conclude that the reduction of disparities between the populations of people with and without disabilities will require specific attention to racial and ethnic disparities in health, insurance coverage, and service use.

First in line: prioritizing receipt of Social Security disability benefits based on likelihood of death during adjudication.

BACKGROUND: Given the complexity of the adjudication process and volume of applications to Social Security Administration's (SSA) disability programs, many individuals with serious medical conditions die while awaiting an application decision. Limitations of traditional survival methods called for a new empirical approach to identify conditions resulting in rapid mortality. OBJECTIVE: To identify health conditions associated with significantly higher mortality than a key reference group among applicants for SSA disability programs. RESEARCH DESIGN: We identified mortality patterns and generated a survival surface for a reference group using conditions already designated for expedited processing. We identified conditions associated with significantly higher mortality than the reference group and prioritized them by the expected likelihood of death during the adjudication process. SUBJECTS: Administrative records of 29 million Social Security disability applicants, who applied for benefits from 1996 to 2007, were analyzed. MEASURES: We computed survival spells from time of onset of disability to death, and from date of application to death. Survival data were organized by entry cohort. RESULTS: In our sample, we observed that approximately 42,000 applicants died before a decision was made on their disability claims. We identified 24 conditions with survival profiles comparable with the reference group. Applicants with these conditions were not likely to survive adjudication. CONCLUSIONS: Our approach facilitates ongoing revision of the conditions SSA designates for expedited awards and has applicability to other programs where survival profiles are a consideration.

Conceptualizing disability in US national surveys: application of the World Health Organization's (WHO) International Classification of Functioning, Disability, and Health (ICF) framework.

PURPOSE: Disability data inform resource allocation and utilization, characterize functioning and changes over time, and provide a mechanism to monitor progress toward promoting and protecting the rights of individuals with disability. Data collection efforts, however, define and measure disability in varied ways. Our objective was to see how the content of disability measures differed in five US national surveys and over time. METHODS: Using the WHO ICF as a conceptual framework for measuring disability, we assessed the National Health Interview Survey (NHIS), Current Population Survey (CPS), Survey of Income and Program Participation (SIPP), National Survey of SSI Children and Families (NSCF), and American Community Survey (ACS) for their content coverage of disability relative to each of the four ICF components (i.e., body functions, body structures, activities and participation, and environment). We used second-level ICF three-digit codes to classify question content into categories within each ICF component and computed the proportion of categories within each ICF component that was represented in the questions selected from these five surveys. RESULTS: The disability measures varied across surveys and years. The NHIS captured a greater proportion of the ICF body functions and body structures components than did other surveys. The SIPP captured the most content of the ICF activities and participation component, and the NSCF contained the most content of the ICF environmental factors component. CONCLUSIONS: This research successfully illustrated demonstrated the utility of the ICF in examining the content of disability measures in five national surveys and over time.

Development of an instrument to measure behavioral health function for work disability: item pool construction and factor analysis.

OBJECTIVES: To develop a broad set of claimant-reported items to assess behavioral health functioning relevant to the Social Security disability determination processes, and to evaluate the underlying structure of behavioral health functioning for use in development of a new functional assessment instrument. DESIGN: Cross-sectional. SETTING: Community. PARTICIPANTS: Item pools of behavioral health functioning were developed, refined, and field tested in a sample of persons applying for Social Security disability benefits (N=1015) who reported difficulties working because of mental or both mental and physical conditions. INTERVENTIONS: None. MAIN OUTCOME MEASURE: Social Security Administration Behavioral Health (SSA-BH) measurement instrument. RESULTS: Confirmatory factor analysis (CFA) specified that a 4-factor model (self-efficacy, mood and emotions, behavioral control, social interactions) had the optimal fit with the data and was also consistent with our hypothesized conceptual framework for characterizing behavioral health functioning. When the items within each of the 4 scales were tested in CFA, the fit statistics indicated adequate support for characterizing behavioral health as a unidimensional construct along these 4 distinct scales of function. CONCLUSIONS: This work represents a significant advance both conceptually and psychometrically in assessment methodologies for work-related behavioral health. The measurement of behavioral health functioning relevant to the context of work requires the assessment of multiple dimensions of behavioral health functioning. Specifically, we identified a 4-factor model solution that represented key domains of work-related behavioral health functioning. These results guided the development and scale formation of a new SSA-BH instrument.

Conceptual foundation for measures of physical function and behavioral health function for Social Security work disability evaluation.

Physical and mental impairments represent the 2 largest health condition categories for which workers receive Social Security disability benefits. Comprehensive assessment of physical and mental impairments should include aspects beyond medical conditions such as a person's underlying capabilities as well as activity demands relevant to the context of work. The objective of this article is to describe the initial conceptual stages of developing new measurement instruments of behavioral health and physical functioning relevant for Social Security work disability evaluation purposes. To outline a clear conceptualization of the constructs to be measured, 2 content models were developed using structured and informal qualitative approaches. We performed a structured literature review focusing on work disability and incorporating aspects of the International Classification of Functioning, Disability and Health as a unifying taxonomy for framework development. Expert interviews provided advice and consultation to enhance face validity of the resulting content models. The content model for work-related behavioral health function identifies 5 major domains: (1) behavior control, (2) basic interactions, (3) temperament and personality, (4) adaptability, and (5) workplace behaviors. The content model describing physical functioning includes 3 domains: (1) changing and maintaining body position, (2) whole-body mobility, and (3) carrying, moving, and handling objects. These content models informed subsequent measurement properties including item development and measurement scale construction, and provided conceptual coherence guiding future empirical inquiry. The proposed measurement approaches show promise to comprehensively and systematically assess physical and behavioral health functioning relevant to work.

Does postacute care site matter? A longitudinal study assessing functional recovery after a stroke.

OBJECTIVE: To determine the impact of postacute care site on stroke outcomes. DESIGN: Prospective cohort study. SETTING: Four northern California hospitals that are part of a single health maintenance organization. PARTICIPANTS: Patients with stroke (N=222) enrolled between February 2008 and July 2010. INTERVENTION: Not applicable. MAIN OUTCOME MEASURE: Baseline and 6-month assessments were performed using the Activity Measure for Post Acute Care (AM-PAC), a test of self-reported function in 3 domains: Basic Mobility, Daily Activities, and Applied Cognition. RESULTS: Of the 222 patients analyzed, 36% went home with no treatment, 22% received home health/outpatient care, 30% included an inpatient rehabilitation facility (IRF) in their care trajectory, and 13% included a skilled nursing facility (but not IRF) in their care trajectory. At 6 months, after controlling for important variables such as age, functional status at acute care discharge, and total hours of rehabilitation, patients who went to an IRF had functional scores that were at least 8 points higher (twice the minimally detectable change for the AM-PAC) than those who went to a skilled nursing facility in all 3 domains and in 2 of 3 functional domains compared with those who received home health/outpatient care. CONCLUSIONS: Patients with stroke may make more functional gains if their postacute care includes an IRF. This finding may have important implications as postacute care delivery is reshaped through health care reform.

Development of a computer-adaptive physical function instrument for Social Security Administration disability determination.

OBJECTIVES: To develop and test an instrument to assess physical function for Social Security Administration (SSA) disability programs, the SSA-Physical Function (SSA-PF) instrument. Item response theory (IRT) analyses were used to (1) create a calibrated item bank for each of the factors identified in prior factor analyses, (2) assess the fit of the items within each scale, (3) develop separate computer-adaptive testing (CAT) instruments for each scale, and (4) conduct initial psychometric testing. DESIGN: Cross-sectional data collection; IRT analyses; CAT simulation. SETTING: Telephone and Internet survey. PARTICIPANTS: Two samples: SSA claimants (n=1017) and adults from the U.S. general population (n=999). INTERVENTIONS: None. MAIN OUTCOME MEASURES: Model fit statistics, correlation, and reliability coefficients. RESULTS: IRT analyses resulted in 5 unidimensional SSA-PF scales: Changing & Maintaining Body Position, Whole Body Mobility, Upper Body Function, Upper Extremity Fine Motor, and Wheelchair Mobility for a total of 102 items. High CAT accuracy was demonstrated by strong correlations between simulated CAT scores and those from the full item banks. On comparing the simulated CATs with the full item banks, very little loss of reliability or precision was noted, except at the lower and upper ranges of each scale. No difference in response patterns by age or sex was noted. The distributions of claimant scores were shifted to the lower end of each scale compared with those of a sample of U.S. adults. CONCLUSIONS: The SSA-PF instrument contributes important new methodology for measuring the physical function of adults applying to the SSA disability programs. Initial evaluation revealed that the SSA-PF instrument achieved considerable breadth of coverage in each content domain and demonstrated noteworthy psychometric properties.

Development of a self-report physical function instrument for disability assessment: item pool construction and factor analysis.

OBJECTIVES: To build a comprehensive item pool representing work-relevant physical functioning and to test the factor structure of the item pool. These developmental steps represent initial outcomes of a broader project to develop instruments for the assessment of function within the context of Social Security Administration (SSA) disability programs. DESIGN: Comprehensive literature review; gap analysis; item generation with expert panel input; stakeholder interviews; cognitive interviews; cross-sectional survey administration; and exploratory and confirmatory factor analyses to assess item pool structure. SETTING: In-person and semistructured interviews and Internet and telephone surveys. PARTICIPANTS: Sample of SSA claimants (n=1017) and a normative sample of adults from the U.S. general population (n=999). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Model fit statistics. RESULTS: The final item pool consisted of 139 items. Within the claimant sample, 58.7% were white; 31.8% were black; 46.6% were women; and the mean age was 49.7 years. Initial factor analyses revealed a 4-factor solution, which included more items and allowed separate characterization of: (1) changing and maintaining body position, (2) whole body mobility, (3) upper body function, and (4) upper extremity fine motor. The final 4-factor model included 91 items. Confirmatory factor analyses for the 4-factor models for the claimant and the normative samples demonstrated very good fit. Fit statistics for claimant and normative samples, respectively, were: Comparative Fit Index=.93 and .98; Tucker-Lewis Index=.92 and .98; and root mean square error approximation=.05 and .04. CONCLUSIONS: The factor structure of the physical function item pool closely resembled the hypothesized content model. The 4 scales relevant to work activities offer promise for providing reliable information about claimant physical functioning relevant to work disability.

Scale refinement and initial evaluation of a behavioral health function measurement tool for work disability evaluation.

OBJECTIVE: To use item response theory (IRT) data simulations to construct and perform initial psychometric testing of a newly developed instrument, the Social Security Administration Behavioral Health Function (SSA-BH) instrument, that aims to assess behavioral health functioning relevant to the context of work. DESIGN: Cross-sectional survey followed by IRT calibration data simulations. SETTING: Community. PARTICIPANTS: Sample of individuals applying for Social Security Administration disability benefits: claimants (n=1015) and a normative comparative sample of U.S. adults (n=1000). INTERVENTIONS: None. MAIN OUTCOME MEASURE: SSA-BH measurement instrument. RESULTS: IRT analyses supported the unidimensionality of 4 SSA-BH scales: mood and emotions (35 items), self-efficacy (23 items), social interactions (6 items), and behavioral control (15 items). All SSA-BH scales demonstrated strong psychometric properties including reliability, accuracy, and breadth of coverage. High correlations of the simulated 5- or 10-item computer adaptive tests with the full item bank indicated robust ability of the computer adaptive testing approach to comprehensively characterize behavioral health function along 4 distinct dimensions. CONCLUSIONS: Initial testing and evaluation of the SSA-BH instrument demonstrated good accuracy, reliability, and content coverage along all 4 scales. Behavioral function profiles of Social Security Administration claimants were generated and compared with age- and sex-matched norms along 4 scales: mood and emotions, behavioral control, social interactions, and self-efficacy. Using the computer adaptive test-based approach offers the ability to collect standardized, comprehensive functional information about claimants in an efficient way, which may prove useful in the context of the Social Security Administration's work disability programs.

Development of an ontology to characterize mental functioning.

PURPOSE OF THE ARTICLE: This article describes a conceptual and methodological approach to integrating functional information into an ontology to categorize mental functioning, which to date is an under-developed area of classification, and supports our work with the United States (U.S.) Social Security Administration (SSA). DESIGN AND METHODOLOGICAL PROCEDURES: Conceptualizing and defining mental functioning was paramount to develop natural language processing (NLP) tools to support our use case. The International Classification of Functioning, Disability, and Health (ICF) was the framework used to conceptualize mental functioning at the activities and participation level in clinical records. To address challenges that arose when applying the ICF as to what should or should not be classified as mental functioning, a mental functioning domain ontology was developed that rearranged, reclassified and incorporated all ICF key components, concepts, classifications, and their definitions. CONCLUSIONS: Challenges emerged in the extent to which we could directly align components in the ICF into an applied ontology of mental functioning. These conceptual challenges required rearrangement of ICF components to adequately support our use case within the social security disability determination process. Findings also have implications to support future NLP efforts for behavioral health outcomes and policy research.

Mental functioning in everyday life is an important area of inquiry from the perspectives of public health, health policy, healthcare, and overall individual level health and well-being.A domain ontology of mental functioning that defines concepts and their relationships, and provides a common terminology with definitions, would enable interdisciplinary communication, research, and collaboration.A clearer conceptual model of mental functioning can improve the development of software that can identify, codify, and organize mental functioning information within clinical records into data that can be analyzed.The International Classification of Functioning, Disability and Health was utilized to conceptualize mental functioning and to guide the development of a proposed domain ontology of mental functioning.

Informatics Research on Mental Health Functioning: Decision Support for the Social Security Administration Disability Program.

The disability determination process of the Social Security Administration's (SSA's) disability program requires assessing work-related functioning for individual claimants alleging disability due to mental impairment. This task is particularly challenging because the determination process involves the review of a large file of information, including objective medical evidence and self-reports from claimants, families, and former employers. To improve this decision-making process, SSA entered an interagency agreement with the Rehabilitation Medicine Department, Epidemiology and Biostatistics Section, in the Clinical Center of the National Institutes of Health, intending to use data science and informatics to develop decision support tools. This collaborative effort over the past decade has led to the development of the Work Disability-Functional Assessment Battery and has initiated an approach to applying natural language processing to the review of claimants' files for information on mental health functioning. This informatics research collaboration holds promise for improving the process of disability determination for individuals with mental impairments who make claims at the SSA.

Linking job duties, functioning, and employment status using the Work-Disability Functional Assessment Battery (WD-FAB): An expert coding and quantitative analysis.

BACKGROUND: An understanding of the link between specific occupational demands and individual worker functioning is limited, although such information could permit an assessment of the fit between the two in a manner that would inform national and state disability programs such as vocational rehabilitation and Social Security disability programs. OBJECTIVE: Our goal was to examine the utility of assessing physical and mental functioning relative to self-reported job duties to identify the domains of worker functioning most likely to create barriers to fulfilling an occupation's specific requirements. METHODS: Through primary survey data collection, 1770 participants completed the Work-Disability Functional Assessment Battery (WD-FAB) instrument after reporting details on their occupations (or most recent occupation if not working). Expert coders evaluated the level of function expected to successfully carry out each self-reported job duty with respect to six scales of physical and mental function. Quantitative analysis is used to examine the relationship between functioning and job duties. RESULTS: Those not working due to disability were more likely to fall short of the threshold of the physical and mental functioning requirements of their last job's three main job duties compared to those currently employed. Mental function scales were most likely to be the area experiencing a shortfall. CONCLUSIONS: Functional difficulties impede the ability to continue working in particular jobs that require that ability. This points to a need for specific accommodations to be implemented to bridge the gap between job requirements and functional capacity so that workers may remain engaged in their current work.

Evaluation of patient and proxy responses on the activity measure for postacute care.

BACKGROUND AND PURPOSE: Our objective was to examine the agreement between adult patients with stroke and family member or clinician proxies in activity measure for postacute care (AM-PAC) summary scores for daily activity, basic mobility, and applied cognitive function. METHODS: This study involved 67 patients with stroke admitted to a hospital within the Kaiser Permanente of Northern California system and were participants in a parent study on stroke outcomes. Each participant and proxy respondent completed the AM-PAC by personal or telephone interview at the point of hospital discharge or during ≥1 transitions to different postacute care settings. RESULTS: The results suggest that for patients with a stroke proxy, AM-PAC data are robust for family or clinician proxy assessment of basic mobility function and clinician proxy assessment of daily activity function, but less robust for family proxy assessment of daily activity function and for all proxy groups' assessments of applied cognitive function. The pattern of disagreement between patient and proxy was, on average, relatively small and random. There was little evidence of systematic bias between proxy and patient reports of their functional status. The degree of concordance between patient and proxy was similar for those with moderate to severe strokes compared with mild strokes. CONCLUSIONS: Patient and proxy ratings on the AM-PAC achieved adequate agreement for use in stroke research when using proxy respondents could reduce sample selection bias. The AM-PAC data can be implemented across institutional as well as community care settings while achieving precision and reducing respondent burden.

Regularized Bayesian calibration and scoring of the WD-FAB IRT model improves predictive performance over marginal maximum likelihood.

Item response theory (IRT) is the statistical paradigm underlying a dominant family of generative probabilistic models for test responses, used to quantify traits in individuals relative to target populations. The graded response model (GRM) is a particular IRT model that is used for ordered polytomous test responses. Both the development and the application of the GRM and other IRT models require statistical decisions. For formulating these models (calibration), one needs to decide on methodologies for item selection, inference, and regularization. For applying these models (test scoring), one needs to make similar decisions, often prioritizing computational tractability and/or interpretability. In many applications, such as in the Work Disability Functional Assessment Battery (WD-FAB), tractability implies approximating an individual's score distribution using estimates of mean and variance, and obtaining that score conditional on only point estimates of the calibrated model. In this manuscript, we evaluate the calibration and scoring of models under this common use-case using Bayesian cross-validation. Applied to the WD-FAB responses collected for the National Institutes of Health, we assess the predictive power of implementations of the GRM based on their ability to yield, on validation sets of respondents, ability estimates that are most predictive of patterns of item responses. Our main finding indicates that regularized Bayesian calibration of the GRM outperforms the regularization-free empirical Bayesian procedure of marginal maximum likelihood. We also motivate the use of compactly supported priors in test scoring.

Extracting body function information using rule-based methods: Highlighting structure and formatting challenges in clinical text.

This paper describes the identification of body function (BF) mentions within the clinical text within a large, national, heterogeneous corpus to highlight structural challenges presented by the clinical text. BF in clinical documents provides information on dysfunction or impairments in the function or structure of organ systems or organs. BF mentions are embedded in highly formatted structures where the formats include implied scoping boundaries that confound existing natural language processing segmentation and document decomposition techniques. This paper describes follow-up work to adapt a rule-based system created using National Institutes of Health records to a larger, more challenging corpus of Social Security Administration data. Results of these systems provide a baseline for future work to improve document decomposition techniques.