Considerations for Evaluating and Recommending Worker Productivity Outcome Measures: An Update from the OMERACT Worker Productivity Group

Thresholds for unacceptable work state in radiographic axial spondyloarthritis of four presenteeism and two clinical outcome measurement instruments

OBJECTIVES

To (i) identify threshold values of presenteeism measurement instruments that reflect unacceptable work state in employed r-axSpA patients; (ii) determine whether those thresholds accurately predict future adverse work outcomes (AWO) (sick leave or short/long-term disability); (iii) evaluate the performance of traditional health-outcomes for r-axSpA; and (iv) explore whether thresholds are stable across contextual factors.

METHODS

Data from the multinational AS-PROSE study was used. Thresholds to determine whether patients consider themselves in an 'unacceptable work state' were calculated at baseline for four instruments assessing presenteeism and two health outcomes specific for r-axSpA. Different approaches derived from the receiver operating characteristic methodology were used. Validity of the optimal thresholds was tested across contextual factors and for predicting future AWO over 12 months.

RESULTS

Of 366 working patients, 15% reported an unacceptable work state; 6% experienced at least one AWO in 12 months. Optimal thresholds were: WPAI-presenteeism ≥40 (AUC 0.85), QQ-method <97 (0.76), WALS ≥0.75 (AUC 0.87), WLQ-25 ≥ 29 (AUC 0.85). BASDAI and BASFI performed similarly to the presenteeism instruments: ≥4.7 (AUC 0.82) and ≥3.5 (AUC 0.79), respectively. Thresholds for WALS and WLQ-25 were stable across contextual factors, while for all other instruments they overestimated unacceptable work state in lower educated persons. Proposed thresholds could also predict future AWO, although with lower performance, especially for QQ-method, BASDAI and BASFI.

CONCLUSIONS

Thresholds of measurement instruments for presenteeism and health status to identify unacceptable work state have been established. These thresholds can help in daily clinical practice to provide work-related support to r-axSpA patients at risk for AWO.

Improvement in work productivity among psoriatic arthritis patients treated with biologic or targeted synthetic drugs: a systematic literature review and meta-analysis

BACKGROUND

Capacity to work is impacted by psoriatic arthritis (PsA). Our objective was to describe the course of work productivity and leisure activity in patients with PsA treated with biologic (b) and targeted synthetic (ts) disease-modifying antirheumatic drugs (DMARDs).

METHODS

A systematic literature review identified all trials and observational studies published January 1, 2010-October 22, 2021, reporting work productivity using the Work Productivity and Activity Impairment Questionnaire (WPAI) in patients with PsA treated with b/tsDMARDs. Outcomes for WPAI domains (absenteeism, presenteeism, total work productivity, and activity impairment) were collected at baseline and time point closest to 24 weeks of treatment. A random effects meta-analysis of single means was conducted to calculate an overall absolute mean change from baseline for each WPAI domain.

RESULTS

Twelve studies (ten randomized controlled and two observational) assessing patients treated with adalimumab, bimekizumab, guselkumab, ixekizumab, risankizumab, secukinumab, or upadacitinib were analysed. Among 3741 employed patients, overall mean baseline scores were 11.4%, 38.7%, 42.7%, and 48.9% for absenteeism, presenteeism, total work productivity impairment, and activity impairment, respectively. Estimated absolute mean improvements (95% confidence interval) to week 24 were 2.4 percentage points (%p) (0.6, 4.1), 17.8%p (16.2,19.3), 17.6%p (15.9,19.4), and 19.3%p (17.6, 21.0) respectively, leading to a mean relative improvement of 41% for total work productivity. The change in work outcomes in the b/tsDMARDs appeared similar.

CONCLUSIONS

This systematic literature review and meta-analysis confirmed that patients with active PsA have a substantially reduced capacity to work and participate in leisure activities. Substantial improvements across various WPAI domains were noted after 24 weeks of b/tsDMARD treatment, especially in presenteeism, total work productivity, and activity impairment. These findings may be useful for reimbursement purposes and in the context of shared decision-making. This systematic literature review (SLR) of randomized clinical trials and observational studies of biologic (b) and targeted synthetic (ts) disease-modifying antirheumatic drugs b/tsDMARDs in patients with PsA found that at treatment introduction, patients presented with a 42.7% mean productivity loss per week as assessed by the Work Productivity and Activity Impairment (WPAI) Questionnaire. Through a meta-analysis comparing before/after values without adjustment for placebo response, we found that after 24 weeks of treatment with b/tsDMARDs, there was a mean absolute improvement of 17.6 percentage points and a mean relative improvement of 41% in total work productivity, with similar magnitudes of improvement in time spent at work and regular activities outside of work. These results provide clinical-, regulatory- and reimbursement decision-makers with data on the potential societal and socio-economic benefits of b/tsDMARDs in PsA.

Work productivity in patients with axial spondyloarthritis initiating biological or targeted synthetic disease-modifying antirheumatic drugs: a systematic literature review and meta-analysis

BACKGROUND

Axial spondyloarthritis (axSpA) can limit work participation. Our objective was to characterise productivity in patients with axSpA, including changes after 12-16 weeks of treatment with biological and targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs).

METHODS

A systematic literature review identified studies published from 1 January 2010 to 21 October 2021 reporting work productivity using the Work Productivity and Activity Impairment (WPAI) questionnaire in patients with axSpA initiating b/tsDMARDs. Baseline and Week 12-16 overall work productivity, absenteeism, presenteeism and activity impairment scores were used in a random-effects meta-analysis to calculate absolute mean change from baseline for each WPAI-domain.

RESULTS

Eleven studies in patients with axSpA who received either placebo (n=727) or treatment with adalimumab, bimekizumab, etanercept, ixekizumab, secukinumab or tofacitinib (n=994) were included. In working patients initiating a b/tsDMARD, mean baseline overall work productivity impairment, absenteeism and presenteeism scores were 52.1% (N=7 studies), 11.0% and 48.8% (N=6 studies), respectively. At Week 12-16, the pooled mean change from baseline in overall work impairment for b/tsDMARDs or placebo was -21.6% and -12.3%. When results were extrapolated to 1 year, the potential annual reductions in cost of paid and unpaid productivity loss per patient ranged from €11 962.88 to €14 293.54.

CONCLUSIONS

Over 50% of employed patients with active axSpA experienced work impairment, primarily due to presenteeism. Overall work productivity improved at Weeks 12-16 to a greater extent for patients who received b/tsDMARDs than placebo. Work productivity loss was associated with a substantial cost burden, which was reduced with improvements in impairment.

Work limitations and associated factors in rheumatoid arthritis, axial spondyloarthritis, osteoarthritis and fibromyalgia

INTRODUCTION

Rheumatic and musculoskeletal diseases (RMD) impact on work participation. The aims of this study were to: examine work limitations of working people with: rheumatoid arthritis, axial spondyloarthritis (axSpA), osteoarthritis, or fibromyalgia using the Workplace Activity Limitations Scale (WALS, a measure of presenteeism); and identify personal, functioning and disability, and work contextual factors associated with presenteeism.

METHODS

Secondary analysis was conducted of a cross-sectional survey including work outcome measures (WORK-PROM study). A literature review identified variables (coded to ICF) to include in multivariable regressions examining factors associated with presenteeism.

RESULTS

Moderate to high WALS scores were identified in: 93.60% with FM; 69.90% OA; 65.20% RA; and 46.80% axSpA (n = 822). Similarities in work limitations were noted across conditions, although some more problematic in specific RMD. Participants received help with about a quarter of activities (27%RA; 25%FM; 23%OA; 17%axSpA) and work adaptations for less than a fifth causing difficulty (18%FM; 14%RA; 14%OA; 9%axSpA). Literature review identified 33 variables in the WORK-PROM dataset to include in multivariable regressions. Factors associated with higher WALS scores were worse: functional limitations, job strain, pain, difficulties with mental-interpersonal job demands, perceived health status, work-life balance, greater need for work accommodations and lack of perceived work support.

DISCUSSION

This study extends understanding of work limitations of working people with these four RMD, the extent of help and adaptations received, need for more work accommodation support, and focus on work support, work rehabilitation, and healthy workplace practices to help keep people working.

Which outcomes should always be measured in intervention studies for improving work participation for people with a health problem? An international multistakeholder Delphi study to develop a core outcome set for Work participation (COS for Work)

OBJECTIVE

Synthesising evidence of the effects of interventions to improve work participation among people with health problems is currently difficult due to heterogeneity in outcome measurements. A core outcome set for work participation is needed.

STUDY DESIGN AND SETTING

Following the Core Outcome Measures in Effectiveness Trials methodology, we used a five-step approach to reach international multistakeholder consensus on a core outcome set for work participation. Five subgroups of stakeholders took part in two rounds of discussions and completed two Delphi voting rounds on 26 outcomes. A consensus of ≥80% determined core outcomes and 50%-80% consensus was required for candidate outcomes.

RESULTS

Fifty-eight stakeholders took part in the Delphi rounds. Core outcomes were: 'any type of employment including self-employment', 'proportion of workers that return to work after being absent because of illness' and 'time to return to work'. Ten candidate outcomes were proposed, among others: 'sustainable employment', 'work productivity' and 'workers' perception of return to work'.

CONCLUSION

As a minimum, all studies evaluating the impact of interventions on work participation should include one employment outcome and two return to work outcomes if workers are on sick leave prior to the intervention.

EULAR Points to Consider (PtC) for designing, analysing and reporting of studies with work participation as an outcome domain in patients with inflammatory arthritis

BACKGROUND

Clinical studies with work participation (WP) as an outcome domain pose particular methodological challenges that hamper interpretation, comparison between studies and meta-analyses.

OBJECTIVES

To develop Points to Consider (PtC) for design, analysis and reporting of studies of patients with inflammatory arthritis that include WP as a primary or secondary outcome domain.

METHODS

The EULAR Standardised Operating Procedures were followed. A multidisciplinary taskforce with 22 experts including patients with rheumatic diseases, from 10 EULAR countries and Canada, identified methodologic areas of concern. Two systematic literature reviews (SLR) appraised the methodology across these areas. In parallel, two surveys among professional societies and experts outside the taskforce sought for additional methodological areas or existing conducting/reporting recommendations. The taskforce formulated the PtC after presentation of the SLRs and survey results, and discussion. Consensus was obtained through informal voting, with levels of agreement obtained anonymously.

RESULTS

Two overarching principles and nine PtC were formulated. The taskforce recommends to align the work-related study objective to the design, duration, and outcome domains/measurement instruments of the study (PtC: 1-3); to identify contextual factors upfront and account for them in analyses (PtC: 4); to account for interdependence of different work outcome domains and for changes in work status over time (PtC: 5-7); to present results as means as well as proportions of patients reaching predefined meaningful categories (PtC: 8) and to explicitly report volumes of productivity loss when costs are an outcome (PtC:9).

CONCLUSION

Adherence to these EULAR PtC will improve the methodological quality of studies evaluating WP.

Methodological aspects of design, analysis and reporting of studies with work participation as an outcome domain in patients with inflammatory arthritis: results of two systematic literature reviews informing EULAR points to consider

Objective

To summarise the methodological aspects in studies with work participation (WP) as outcome domain in inflammatory arthritis (IA) and other chronic diseases.

Methods

Two systematic literature reviews (SLRs) were conducted in key electronic databases (2014–2019): search 1 focused on longitudinal prospective studies in IA and search 2 on SLRs in other chronic diseases. Two reviewers independently identified eligible studies and extracted data covering pre-defined methodological areas.

Results

In total, 58 studies in IA (22 randomised controlled trials, 36 longitudinal observational studies) and 24 SLRs in other chronic diseases were included. WP was the primary outcome in 26/58 (45%) studies. The methodological aspects least accounted for in IA studies were as follows (proportions of studies positively adhering to the topic are shown): aligning the studied population (16/58 (28%)) and sample size calculation (8/58 (14%)) with the work-related study objective; attribution of WP to overall health (28/58 (48%)); accounting for skewness of presenteeism/sick leave (10/52 (19%)); accounting for work-related contextual factors (25/58 (43%)); reporting attrition and its reasons (1/58 (2%)); reporting both aggregated results and proportions of individuals reaching predefined meaningful change or state (11/58 (16%)). SLRs in other chronic diseases confirmed heterogeneity and methodological flaws identified in IA studies without identifying new issues.

Conclusion

High methodological heterogeneity was observed in studies with WP as outcome domain. Consensus around various methodological aspects specific to WP studies is needed to improve quality of future studies. This review informs the EULAR Points to Consider for conducting and reporting studies with WP as an outcome in IA.

Cost assessment of health interventions and diseases

Health resource use and identification of related costs are two essential steps in health economics assessment. The elicited costs will be balanced with health outcome improvement and enable the comparison of different diagnostic procedures or therapeutic strategies from a health economic point of view. The cost typology can be disentangled in three main components, that is, direct cost related to health resource use, indirect costs related to productivity loss and sometimes intangible costs (costs related to pain and suffering). These costs can be elicited from different perspectives depending on the general aim of the assessment: payer, societal perspective or patient perspective. Practically, the first step corresponds to the quantification of health resource use, that is, number of consultations, biological or imaging workups, hospitalisation, dispensed medication units or days on sick leave. It can be done by specific self-questionnaires or by access to insurance health databases. The second step is then to value each health resource use item, based on available public databases—either produced by insurance entities or statistics institute—providing the unit costs for each item. Importantly, substantial variability does exist in the costing exercise, requiring accepting a certain uncertainty around cost estimates. This can be taken into account by sensitivity analyses, which capture in what extent measurement error can impact cost assessment, depending on different hypotheses or assumptions. One essential element of health economic assessment is the identification of costs incurred by or associated with a specific health condition for a study on the economic burden of a disease—cost-of-illness study—or with a given diagnostic or therapeutic intervention in the context of health technology assessment in which these costs are compared with the alternative reference strategy—cost-effectiveness study.

Employment outcomes in systemic sclerosis

Work disability is highly prevalent in the systemic sclerosis (SSc) population; yet, it is an area of research that continues to be underrecognized and underexplored. In this chapter, we review the burden of this work disability by exploring the reported prevalence of work loss, the risk factors associated with reduced work participation, the impact on work productivity outcomes, and the economic consequences of work disability in individuals with SSc. Finally, we discuss the potential challenges in the workplace and strategies that may foster employment retention in this population. We subsequently present a conceptual framework for work disability in the context of SSc, which incorporates our understanding of the various work disability concepts and the potential facilitators that may accelerate a worker toward complete work loss.

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 effect on work presenteeism of job retention vocational rehabilitation compared to a written self-help work advice pack for employed people with inflammatory arthritis: protocol for a multi-centre randomised controlled trial (the WORKWELL trial)

Background

Work problems are common in people with inflammatory arthritis. Up to 50% stop work within 10 years due to their condition and up to 67% report presenteeism (i.e. reduced work productivity), even amongst those with low disease activity. Job retention vocational rehabilitation (JRVR) may help prevent or postpone job loss and reduce presenteeism through work assessment, work-related rehabilitation and enabling job accommodations. This aims to create a better match between the person’s abilities and their job demands. The objectives of the Workwell trial are to test the overall effectiveness and cost-effectiveness of JRVR (WORKWELL) provided by additionally trained National Health Service (NHS) occupational therapists compared to a control group who receive self-help information both in addition to usual care.

Methods

Based on the learning from a feasibility trial (the WORK-IA trial: ISRCTN76777720), the WORKWELL trial is a multi-centre, pragmatic, individually-randomised parallel group superiority trial, including economic evaluation, contextual factors analysis and process evaluation. Two hundred forty employed adults with rheumatoid arthritis, undifferentiated inflammatory arthritis or psoriatic arthritis (in secondary care), aged 18 years or older with work instability will be randomised to one of two groups: a self-help written work advice pack plus usual care (control intervention); or WORKWELL JRVR plus a self-help written work advice pack and usual care. WORKWELL will be delivered by occupational therapists provided with additional JRVR training from the research team. The primary outcome is presenteeism as measured using the Work Limitations Questionnaire-25. A comprehensive range of secondary outcomes of work, health, contextual factors and health resource use are included. Outcomes are measured at 6- and 12- months (with 12-months as the primary end-point). A multi-perspective within-trial cost-effectiveness analyses will also be conducted.

Discussion

This trial will contribute to the evidence base for provision of JRVR to people with inflammatory arthritis. If JRVR is found to be effective in enabling people to keep working, the findings will support decision-making about provision of JRVR by rheumatology teams, therapy services and healthcare commissioners, and providing evidence of the effectiveness of JRVR and the economic impact of its implementation.

Trial registration

Clinical Trials.Gov: NCT03942783. Registered 08/05/2019 (https://clinicaltrials.gov/ct2/show/NCT03942783); ISRCTN Registry: ISRCTN61762297. Registered:13/05/2019 (http://www.isrctn.com/ISRCTN61762297). Retrospectively registered.