Confirmatory factor analysis of the Work Limitations Questionnaire (WLQ-25) in Workers' Compensation Claimants with chronic upper-limb disorders

Psychometric properties of the Work Limitations Questionnaire applied to nursing workers

OBJECTIVE

to evaluate the psychometric properties of the Work Limitations Questionnaire and to measure presenteeism in a sample of nursing workers.

METHOD

a cross-sectional study, with non-probabilistic sampling. Data was collected between July 2018 and February 2019 in two high-complexity hospitals, and the sample was composed of 304 participants. The validity analysis of the Work Limitations Questionnaire was performed by means of Confirmatory Factor Analysis.

RESULTS

most of the participants were women (88.5%), with a mean age of 40.9 years old. The validities of the factorial, convergent and discriminant construct and the reliability of the complete version and of the 16-item version of the instrument were adequate after adjusting the models to the sample. A statistically significant and negative correlation (p<0.001) was verified between the workload, working time and the Time Management and Physical Demands dimensions; as well as a statistically significant (p<0.001) correlation between working time and the Mental-Interpersonal Demands and Production Demands dimensions. Gender and professional category did not influence presenteeism. The rate of loss of productivity at work was 19.51%.

CONCLUSION

the Work Limitations Questionnaire showed adequate validity and reliability and can be considered a valid and reliable instrument for assessing presenteeism in the nursing team.

Evaluation of the Structural Validity of the Work Instability Scale Using the Rasch Model

Objective

To use Rasch analysis to examine the measurement properties of the 23-item version of the Work Instability Scale (WIS-23) in a sample of worker compensation claimants with upper extremity disorders.

Design

Secondary data analysis on the data retrieved from a cross-sectional study.

Setting

Tertiary care hospital.

Participants

Patients (N=392) attending a specialty clinic for workers with upper limb injuries at a tertiary hospital were prospectively enrolled.

Interventions

Not applicable.

Main Outcome Measures

WIS-23.

Results

The study sample contained 392 participants between the ages of 19 and 73 years (mean, 47.0±10.5y). There were 148 (37.8%) women, 182 (46.4%) men, and 62 (15.8%) participants for whom sex identification was unavailable. The initial WIS data analysis showed significant misfit from the Rasch model (item-trait interaction: χ²=293.52; P<.0001). Item removal and splitting were performed to improve the model fit, resulting in a 20-item scale that met all assumptions (χ²=160.42; P=.008), including unidimensionality, local independence of items, and the absence of differential item function based on age, sex of respondents, employment type, and affected upper extremity area across all tested factors.

Conclusion

With the application of Rasch analysis, we refined the WIS-23 to produce a 20-item WIS for work-related upper extremity disorders (WIS-WREUD). The 20-item WIS-WREUD demonstrated excellent item and person fit, unidimensionality, acceptable person separation index, and local independency. The WIS-20 may provide better measurement properties, although longitudinal psychometric evaluations are needed.

An Evaluation of the Structural Validity of the Work Limitation Questionnaire Using the Rasch Model

OBJECTIVE

To investigate the targeting, scaling, and structural validity of the Work Limitation Questionnaire (WLQ) using Rasch analysis.

DESIGN

Secondary data analysis.

SETTING

Tertiary care hospital.

PARTICIPANTS

The data were sourced from an upper limb specialty clinic of injured workers using the convenience sampling method and from a national randomized controlled trial investigating 2 surgical options for rotator cuff repair by formal, randomized selection (N=315).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Work Limitation Questionnaire 25-item version (WLQ-25). The WLQ contains 25 items measuring a client's ability to perform specific job demands on a 5-point ordinal response scale ranging from 0 (difficulty none of the time) to 4 (difficulty all the time). The average of all 25 items is used as the total score, ranging from 0 to 4, where higher index scores indicate greater difficulty performing daily work. Subscales were used to assess time management, physical demands (PD), mental-interpersonal demands, and output demands.

RESULTS

The Rasch analyses performed on the dataset included the test of fit of residuals, ordering of item thresholds, Person separation index, differential item functioning (DIF), dependency, and unidimensionality. The partial credit model was selected for the current Rasch analysis because the likelihood ratio test was significant at both the overall questionnaire and the subscale level (P<.001). The WLQ-25 did not fit with the Rasch model (χ²=1715.58; df=125; P<.001) and most of the thresholds were disordered. A series of steps were undertaken to improve the fit statistic, including item reduction (6 items) and response merging (9 items). DIF was absent in the revised scale based on sex, age, full- or part-time employment, and type of employment. Only 3 revised subscales, namely the PD, mental demands, and interpersonal demands subscales, demonstrated acceptable fit to the Rasch model.

CONCLUSIONS

The WLQ-25 demonstrated substantial misfit from the Rasch model, which could not be fully mediated. The revised PD, mental demands, and interpersonal demands subscales could be used to assess these constructs.

The Work Role Functioning Questionnaire v2.0 Showed Consistent Factor Structure Across Six Working Samples

Objective The Work Role Functioning Questionnaire v2.0 (WRFQ) is an outcome measure linking a persons' health to the ability to meet work demands in the twenty-first century. We aimed to examine the construct validity of the WRFQ in a heterogeneous set of working samples in the Netherlands with mixed clinical conditions and job types to evaluate the comparability of the scale structure. Methods Confirmatory factor and multi-group analyses were conducted in six cross-sectional working samples (total N = 2433) to evaluate and compare a five-factor model structure of the WRFQ (work scheduling demands, output demands, physical demands, mental and social demands, and flexibility demands). Model fit indices were calculated based on RMSEA ≤ 0.08 and CFI ≥ 0.95. After fitting the five-factor model, the multidimensional structure of the instrument was evaluated across samples using a second order factor model. Results The factor structure was robust across samples and a multi-group model had adequate fit (RMSEA = 0.63, CFI = 0.972). In sample specific analyses, minor modifications were necessary in three samples (final RMSEA 0.055-0.080, final CFI between 0.955 and 0.989). Applying the previous first order specifications, a second order factor model had adequate fit in all samples. Conclusion A five-factor model of the WRFQ showed consistent structural validity across samples. A second order factor model showed adequate fit, but the second order factor loadings varied across samples. Therefore subscale scores are recommended to compare across different clinical and working samples.

Workability for persons with chronic diseases. A systematic review of validity and utility of assessments in German language / Valide und praktikable deutschsprachige Assessments zur Erfassung der Arbeitsfähigkeit bei Menschen mit chronischen Erkrankungen – eine systematische Review

Background

People with chronic diseases are often limited in their workability. Evaluating and enabling workability is central in rehabilitation. The aim of this study was to evaluate validity and utility of workability assessments in German for persons with chronic diseases.

Methods

The study is a systematic review. First, we systematically searched for literature in the databases Medline, CINAHL, PsycInfo, Cochrane HTA Database, DARE, CCMed, Sowiport, and BASE using following keywords: evaluation tool, chronic disease, workability, validity, and utility. Then, we evaluated the content and the quality of the studies based on criteria and decided if they were included.

Results

In total, validity and utility of eight workability assessments are described based on 74 studies. The assessments are: Productivity Costs Questionnaire (iPCQ), Work Instability Scale for Rheumatoid Arthritis (RA-WIS), Screening-Instrument Arbeit und Beruf (SIBAR), Screening-Instrument zur Feststellung des Bedarfs an medizinisch-beruflich orientierten Maßnahmen in der medizinischen Rehabilitation (SIMBO), Valuation of Lost Productivity Questionnaire (VOLP), Work Ability Index (WAI/ABI), Work Limitations Questionnaire (WLQ), and Work Productivity and Activity Impairment Questionnaire (WPAI).

Conclusion

The results revealed the availability of eight workability assessments for persons with chronic diseases in German language. They have strengths and weaknesses in relation to the construct, purpose, application, and evidence base. These could be the base for choice of an assessment. Overall, we suggest using workability assessment in order to meet the legal requirements for the use of standardized assessments and the increasing demand to establish evidence of the effectiveness of interventions.

The relationship between organizational policies and practices and work limitations among hospital patient care workers

OBJECTIVE

We examined relationships between organizational policies and practices (OPPs) (safety practices, ergonomic practices, and people-oriented culture) and work limitations in a sample of hospital workers.

METHODS

We used the 6-item Work Limitations Questionnaire (WLQ) to assess workers' perceptions of health-related work limitations. Self-reported OPPs and the WLQ were collected from workers in Boston, Massachusetts (n = 1277). We conducted random-intercept multi-level logistic regression models for each OPP using stepwise selection of covariates.

RESULTS

As the unit-average ergonomic practice score increased by one, the odds of a worker reporting work limitations decreased by approximately 39% (P-value = 0.018), adjusted for job title, age, and body mass index. A similar relationship existed for people-oriented culture (P-value = 0.038). The association between safety practices and work limitations was similar, but not statistically significant.

CONCLUSIONS

This study demonstrated the importance of workplace OPPs. OPPs that promote positive and supportive environments and that foster improvements in ergonomics may help reduce work limitations.

Evaluating the validity of the Work Role Functioning Questionnaire (Canadian French version) using classical test theory and item response theory

BACKGROUND

The Work Role Functioning Questionnaire (WRFQ) was developed to assess workers' perceived ability to perform job demands and is used to monitor presenteeism. Still few studies on its validity can be found in the literature.

OBJECTIVE

The purpose of this study was to assess the items and factorial composition of the Canadian French version of the WRFQ (WRFQ-CF).

METHODS

Two measurement approaches were used to test the WRFQ-CF: Classical Test Theory (CTT) and non-parametric Item Response Theory (IRT).

RESULTS

A total of 352 completed questionnaires were analyzed. A four-factor and three-factor model models were tested and shown respectively good fit with 14 items (Root Mean Square Error of Approximation (RMSEA) = 0.06, Standardized Root Mean Square Residual (SRMR) = 0.04, Bentler Comparative Fit Index (CFI) = 0.98) and with 17 items (RMSEA = 0.059, SRMR = 0.048, CFI = 0.98). Using IRT, 13 problematic items were identified, of which 9 were common with CTT.

CONCLUSIONS

This study tested different models with fewer problematic items found in a three-factor model. Using a non-parametric IRT and CTT for item purification gave complementary results. IRT is still scarcely used and can be an interesting alternative method to enhance the quality of a measurement instrument. More studies are needed on the WRFQ-CF to refine its items and factorial composition.

Validity and Reliability of the 8-Item Work Limitations Questionnaire

Purpose To evaluate factorial validity, scale reliability, test-retest reliability, convergent validity, and discriminant validity of the 8-item Work Limitations Questionnaire (WLQ) among employees from a public university system. Methods A secondary analysis using de-identified data from employees who completed an annual Health Assessment between the years 2009-2015 tested research aims. Confirmatory factor analysis (CFA) (n = 10,165) tested the latent structure of the 8-item WLQ. Scale reliability was determined using a CFA-based approach while test-retest reliability was determined using the intraclass correlation coefficient. Convergent/discriminant validity was tested by evaluating relations between the 8-item WLQ with health/performance variables for convergent validity (health-related work performance, number of chronic conditions, and general health) and demographic variables for discriminant validity (gender and institution type). Results A 1-factor model with three correlated residuals demonstrated excellent model fit (CFI = 0.99, TLI = 0.99, RMSEA = 0.03, and SRMR = 0.01). The scale reliability was acceptable (0.69, 95% CI 0.68-0.70) and the test-retest reliability was very good (ICC = 0.78). Low-to-moderate associations were observed between the 8-item WLQ and the health/performance variables while weak associations were observed between the demographic variables. Conclusions The 8-item WLQ demonstrated sufficient reliability and validity among employees from a public university system. Results suggest the 8-item WLQ is a usable alternative for studies when the more comprehensive 25-item WLQ is not available.

The impact of fragility fractures on work and characteristics associated with time to return to work

We examined the impact of fragility fractures on the work outcomes of employed patients. The majority successfully returned to their previous jobs in a short amount of time, and productivity loss at work was low. Our findings underscore the fast recovery rates of working fragility fracture patients.

INTRODUCTION

The purpose of this study is to describe the impact of fragility fractures on the work outcomes of patients who were employed at the time of their fracture.

METHODS

A self-report anonymous survey was mailed to fragility fracture patients over 50 who were screened as part of the quality assurance programs of fracture clinics across 35 hospitals in Ontario, Canada. Measures of return to work (RTW), at-work productivity loss (Work Limitations Questionnaire), and sociodemographic, fracture-related, and job characteristics were included in the survey. Kaplan-Meier estimates of the cumulative proportion of patients still off work were computed. Factors associated with RTW time following a fragility fracture were examined using Cox proportional hazards modeling.

RESULTS

Of 275 participants, 242 (88 %) returned to work. Of these, the median RTW time was 20.5 days. About 86 % returned to the same job, duties, and hours as before their injury. Among full-time workers, the median number of lost hours due to presenteeism was 2.9 h (Q1-Q3 0.4-8.1 h). The median cost of presenteeism was $75.30 based on the month prior to survey completion. In multivariable analyses, female gender, needing surgery, and medium/heavy work requirements were associated with longer RTW time. Earlier RTW time was associated with elbow fracture and feeling completely better at time of survey completion.

CONCLUSIONS

The majority of fragility fracture patients successfully returned to their previous jobs in a short amount of time, and productivity loss at work was low. Our findings underscore their fast recovery rates and give reason for optimism regarding the resilience of this population.

Comparison of Employer Productivity Metrics to Lost Productivity Estimated by Commonly Used Questionnaires

OBJECTIVE

The aim of the study was to assess construct and discriminant validity of four health-related work productivity loss questionnaires in relation to employer productivity metrics, and to describe variation in economic estimates of productivity loss provided by the questionnaires in healthy workers.

METHODS

Fifty-eight billing office workers completed surveys including health information and four productivity loss questionnaires. Employer productivity metrics and work hours were also obtained.

RESULTS

Productivity loss questionnaires were weakly to moderately correlated with employer productivity metrics. Workers with more health complaints reported greater health-related productivity loss than healthier workers, but showed no loss on employer productivity metrics. Economic estimates of productivity loss showed wide variation among questionnaires, yet no loss of actual productivity.

CONCLUSIONS

Additional studies are needed comparing questionnaires with objective measures in larger samples and other industries, to improve measurement methods for health-related productivity loss.

Estimating productivity costs in health economic evaluations: a review of instruments and psychometric evidence

Health economic evaluations (i.e. cost-effectiveness appraisal of an intervention) are useful aids for decision makers responsible for the allocation of scarce healthcare resources. The relevance of including health-related productivity costs (or benefits) in these evaluations is increasingly recognized and, as such, reliable and valid instruments to quantify productivity costs are needed. Over the years, a number of work productivity instruments have emerged in the literature, along with a growing body of psychometric evidence. The overall aim of this paper is to provide a review of available instruments with potential for estimating health-related productivity costs. This included the Health and Labor Questionnaire, Health and Work Performance Questionnaire, Health-Related Productivity Questionnaire Diary, Productivity and Disease Questionnaire, Quantity and Quality method, Stanford Presenteeism Scale 13, Valuation of Lost Productivity, Work and Health Interview, Work Limitations Questionnaire, Work Productivity and Activity Impairment Questionnaire, and Work Productivity Short Inventory. Critical discussions on the instruments' overall strengths and limitations, applicability for health economic evaluations, as well as the methodological quality of existing psychometric evidence were provided. Lastly, a set of reflective questions were proposed for users to consider when selecting an instrument for health economic evaluations.

Worker Productivity Outcome Measures: OMERACT Filter Evidence and Agenda for Future Research

The objective of the Outcome Measures in Rheumatology (OMERACT) Worker Productivity working group is to identify worker productivity outcome measures that meet the requirements of the OMERACT filter. At the OMERACT 11 Workshop, we focused on the at-work limitations/productivity component of worker productivity (i.e., presenteeism) — an area with diverse conceptualization and instrumentation approaches. Various approaches to quantify at-work limitations/productivity (e.g., single-item global and multi-item measures) were examined, and available evidence pertaining to OMERACT truth, discrimination, and feasibility were presented to conference participants. Four candidate global measures of presenteeism were put forth for a plenary vote to determine whether current evidence meets the OMERACT filter requirements. Presenteeism globals from the Work Productivity and Activity Impairment Questionnaire (72% support) and Rheumatoid Arthritis-specific Work Productivity Survey (71% support) were endorsed by conference participants; however, neither the presenteeism global item from the Health and Work Performance Questionnaire nor the Quantity and Quality method achieved the level of support required for endorsement at the present time. The plenary was also asked whether the central item from the Work Ability Index should also be considered as a candidate measure for potential endorsement in the future. Of participants at the plenary, 70% supported this presenteeism global measure. Progress was also made in other areas through discussions at individual breakout sessions. Topics examined include the merits of various multi-item measures of at-work limitations/productivity, methodological issues related to interpretability of outcome scores, and approaches to appraise and classify contextual factors of worker productivity. Feedback gathered from conference participants will inform the future research agenda of the working group.