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.

Validation of the Work-Disability Physical Functional Assessment Battery.

OBJECTIVE: To examine the validity of the self-report Work-Disability Functional Assessment Battery (WD-FAB) physical function scales relative to clinician ratings of function and a performance-based functional capacity evaluation called the Physical Work Performance Evaluation (PWPE). DESIGN: Cross-sectional. SETTING: Outpatient rehabilitation. PARTICIPANTS: Adults (N=50) participating in physical therapy for musculoskeletal conditions. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Patients completed the PWPE and the WD-FAB physical function scales including Changing and Maintaining Body Position, Whole Body Mobility, Upper Body Function, and Upper Extremity Fine Motor. The physical therapist also answered the WD-FAB questions on the patient's physical functioning. The WD-FAB computer-adaptive test version administered up to 10 items for each scale. The PWPE produces ratings from 0 to 5 indicating overall Level of Work ability: 0 (unable to work); 1 (sedentary); 2 (light); 3 (medium); 4 (heavy); 5 (very heavy). The PWPE also produces Level of Work ability ratings in the Dynamic Strength, Position Tolerance, and Mobility subsections. RESULTS: Participating in the study were 50 patients with 1 or more conditions (shoulder, n=21; knee, n=16; low back, n=13; ankle/foot, n=10; neck, n=8; hip, n=7). The patient-based WD-FAB scores demonstrated moderate, statistically significant correlations with the provider proxy WD-FAB report (R=.49-.65). The WD-FAB Upper Body Function scale scores demonstrated moderate strength relationships with the PWPE overall ratings. The Whole Body Mobility and Changing and Maintaining Body Position scales did not demonstrate statistically significant relationships with the PWPE overall ratings. CONCLUSIONS: We found moderate evidence for validity for the WD-FAB Upper Body Function, Whole Body Mobility, and Changing and Maintaining Body Position scales relative to clinician report and varied evidence relative to the PWPE in this clinical sample.

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.

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.

Determining Unmet Needs Among Workers' Compensation Stakeholders to Prevent Work Disability in the State of Vermont.

PURPOSE: Vermont has high rates of young people receiving federal disability benefits leading to substantial gaps in the workforce. The purpose of this project was to determine the unmet needs of interested parties in the workers' compensation (WC) process. METHODS: A type of focus group, experience groups, was used to elicit key parties' experiences in the WC system. Facilitators used open-ended prompts to encourage discussion among participants about their experience with the WC system. Data were analyzed using thematic coding procedures to identify common motifs. RESULTS: Common themes emerged including challenges in navigating the WC system, lack of communication among stakeholders, and providing and receiving appropriate health care to facilitate RTW. CONCLUSIONS: Understanding unmet needs of interested parties in the WC process allows for the creation of targeted, high-value, early intervention strategies to reduce long-term work disability.

Measuring Work Related Physical and Mental Health Function: Updating the Work Disability Functional Assessment Battery (WD-FAB) Using Item Response Theory.

OBJECTIVE: To further improve measurement of work-related physical and mental health by updating the Work Disability Assessment Battery (WD-FAB). METHODS: Cross-sectional study with 1024 disability claimants and 1000 working age (21 to 66 years) adults in the United States. Developed new items to replenish the WD-FAB and analyzed using factor analysis and item response theory (IRT). Computer adaptive testing (CAT) simulations evaluated the psychometric properties of the original versus updated WD-FAB. RESULTS: Analyses confirmed the structure of the WD-FAB. Twenty-three new items were added (basic mobility: 7, upper body function: 4, fine motor: 6, self-regulation: 1, resilience & sociability: 5 items). CONCLUSIONS: Findings support the WD-FAB as a robust, psychometrically sound assessment of work-related function. Extensive content coverage (331 items) represents eight physical and mental health domains. IRT/CAT methods allow administration in under 15 minutes. The WD-FAB may prove valuable for efficiently characterizing work-related function across work rehabilitation settings.