Kenneth Tang

Reliability, validity, and responsiveness of five at‐work productivity measures in patients with rheumatoid arthritis or osteoarthritis

Arthritis often impacts a workers ability to be productive while at work. However, the ideal approach to measuring arthritis‐attributable at‐work productivity loss remains unclear. Our objective was to evaluate the relative strengths and weaknesses of 5 measures aimed at quantifying health‐related at‐work productivity loss and to determine the best available instrument for this population.

Productivity loss due to presenteeism among patients with arthritis: estimates from 4 instruments.

Objective. To estimate and compare lost work hours attributable to presenteeism, defined as reduced productivity while working, in individuals with osteoarthritis (OA) or rheumatoid arthritis (RA), according to 4 instruments. Methods. In our prospective study, 250 workers with OA (n = 130) or RA (n = 120) were recruited from community and clinical sites. Lost hours due to presenteeism at baseline were estimated using the Health and Labor Questionnaire (HLQ), the Work Limitations Questionnaire (WLQ), the World Health Organization’s Health and Work Performance Questionnaire (HPQ), and the Work Productivity and Activity Impairment Questionnaire (WPAI). Only those respondents working over the past 2 weeks were included. Repeated-measures ANOVA was used to compare the lost-time estimates, according to each instrument. Results. Of the 212 respondents included in the analyses, the frequency of missing and “0” values among the instruments was different (17% and 61% for HLQ, 8% and 5% for WLQ, 1% and 16% for HPQ, 0% and 27% for WPAI, respectively). The average numbers of lost hours (SD) per 2 weeks due to presenteeism using HLQ, WLQ, HPQ, and WPAI were 1.6 (3.9), 4.0 (3.9), 13.5 (12.5), and 14.2 (16.7). The corresponding costs for the 2-week period were CAN

Measures of work disability and productivity: Rheumatoid Arthritis Specific Work Productivity Survey (WPS-RA), Workplace Activity Limitations Scale (WALS), Work Instability Scale for Rheumatoid Arthritis (RA-WIS), Work Limitations Questionnaire (WLQ), and Work Productivity and Activity Impairment Questionnaire (WPAI).

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Measurement properties of the QuickDASH (Disabilities of the Arm, Shoulder and Hand) outcome measure and cross-cultural adaptations of the QuickDASH: a systematic review

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Measuring the Impact of Arthritis on Worker Productivity: Perspectives, Methodologic Issues, and Contextual Factors

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Examination of arthritis‐related work place activity limitations and intermittent disability over four‐and‐a‐half years and its relationship to job modifications and outcomes

285.10. The differences in the lost-hour estimates according to instruments were significant (p < 0.001). Conclusion. Among individuals with arthritis, estimates of productivity losses while working vary widely according to the instruments chosen. Further research on instrument design and implications for a standardized approach to estimate lost time due to presenteeism is needed.

Validity and responsiveness of presenteeism scales in chronic work-related upper-extremity disorders.

The impact of arthritis on work is an area of increasing research interest and a growing number of outcome measures to quantify such impact have become available in recent years. Recent reviews from an Outcome Measures in Rheumatology initiative have broadly identified 24 instruments in this area (1,2), though only 11 had been used in arthritis to date. Previous studies have shown that these measures only moderately correlate with each other (3– 10), therefore it is important to recognize that available instruments offer distinct perspectives on health-related work impacts. For example, some measures are aimed at examining degree of difficulties with specific workplace activities, while others are designed to quantify the extent of absenteeism (e.g., number of days off work) and/or presenteeism (e.g., being at work but working at reduced productivity, also referred to as “at-work productivity loss” or “at-work disability”). Also available are instruments focused on assessing related concepts such as work “performance,” “efficiency,” “instability,” or degree of “interference” at work. For the purpose of this review, we have adopted a broader approach and consider a diverse range of available measures that offer varying perspectives and approaches to quantifying the impact of health problems on work (Table 1). Beyond their diverse conceptual foci, existing instruments also differ in terms of their scope of measurement (e.g., impact on employment work versus nonpaid work and/or leisure activities), disease attribution (e.g., disease specific versus generic), length (e.g., number of sections and items), and recall period. Some are designed as “modular” instruments that assess work impacts using a series of global rating scales and discrete items (often organized into multiple sections) that are generally not intended to be summative. Others are classic “psychometric” measures consisting of summative items that inform disease impact on different specific aspects of work (contributes to an overall construct). Specific impacts examined at the item level may include problems meeting the physical demands of work, challenges associated with time management, difficulties maintaining interpersonal relationships at work, cognitive concerns (e.g., worries about continued employability), and/or issues related to symptom control/exacerbation and fatigue. The diversity of available measures is a strength in this growing field and has accommodated the growing interest to apply these tools for a broad range of purposes in arthritis. For example, these measures have been used to examine the epidemiology (e.g., population trends, determinants) of work disability/participation in the arthritis population, to evaluate the effectiveness of clinical or workplace interventions (e.g., clinical trials), and also, to estimate the economic costs of health-related work productivity loss at the societal level. Five specific measures were selected for a detailed review in this article. These were chosen on the basis of 2 Mr. Tang is recipient of a Canadian Institutes of Health Research PhD Fellowship, Canadian Arthritis Network Graduate Award, and Syme Fellowship from the Institute for Work & Health. Dr. Beaton is recipient of a Canadian Institutes of Health Research New Investigators award. Dr. Bombardier is recipient of a Canada Research Chair in Knowledge Transfer for Musculoskeletal Care. Kenneth Tang, MSc(PT), MSc, Dorcas E. Beaton, PhD: St. Michael’s Hospital, Institute for Work & Health, and University of Toronto, Toronto, Ontario, Canada; Annelies Boonen, MD, PhD: Maastricht University Medical Center and Caphri Research Institute, Maastricht, The Netherlands; Monique A. M. Gignac, PhD: Toronto Western Research Institute, University Health Network, and University of Toronto, Toronto, Ontario, Canada; Claire Bombardier, MD: University Health Network, Institute for Work & Health, and University of Toronto, Toronto, Ontario, Canada. Dr. Boonen has received consultancy fees, speaking fees, and/or honoraria (less than

The Work Instability Scale for rheumatoid arthritis predicts arthritis-related work transitions within 12 months

10,000 each) from Abbott and Pfizer. Address correspondence to Kenneth Tang, MSc(PT), MSc, Mobility Program Clinical Research Unit, Li Ka Shing Institute of St. Michael’s Hospital, 30 Bond Street, Toronto, Ontario, Canada. E-mail: ken.tang@utoronto.ca. Submitted for publication January 31, 2011; accepted in revised form May 10, 2011. Arthritis Care & Research Vol. 63, No. S11, November 2011, pp S337–S349 DOI 10.1002/acr.20633

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

PurposeTo identify and synthesize evidence for the measurement properties of the QuickDASH, a shortened version of the 30-item DASH (Disabilities of the Arm, Shoulder and Hand) instrument.MethodsThis systematic review used a best evidence synthesis approach to critically appraise the measurement properties [using COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN)] of the QuickDASH and cross-cultural adaptations. A standard search strategy was conducted between 2005 (year of first publication of QuickDASH) and March 2011 in MEDLINE, EMBASE and CINAHL.ResultsThe search identified 14 studies to include in the best evidence synthesis of the QuickDASH. A further 11 studies were identified on eight cross-cultural adaptation versions.ConclusionsMany measurement properties of the QuickDASH have been evaluated in multiple studies and across most of the measurement properties. The best evidence synthesis of the QuickDASH English version suggests that this tool is performing well with strong positive evidence for reliability and validity (hypothesis testing), and moderate positive evidence for structural validity testing. Strong negative evidence was found for responsiveness due to lower correlations with global estimates of change. Information about the measurement properties of the cross-cultural adaptation versions is still lacking, or the available information is of poor overall methodological quality.

Estimating Productivity Costs in Health Economic Evaluations: A Review of Instruments and Psychometric Evidence

Leading up to the Outcome Measures in Rheumatology (OMERACT) 10 meeting, the goal of the Worker Productivity Special Interest Group (WP-SIG) was to make progress on 3 key issues that relate to the application and interpretation of worker productivity outcomes in arthritis: (1) to review existing conceptual frameworks to help consolidate our intended target and scope of measurement; (2) to examine the methodologic issues associated with our goal of combining multiple indicators of worker productivity loss (e.g., absenteeism <—> presenteeism) into a single comprehensive outcome; and (3) to examine the relevant contextual factors of work and potential implications for the interpretation of scores derived from existing outcome measures. Progress was made on all 3 issues at OMERACT 10. We identified 3 theoretical frameworks that offered unique but converging perspectives on worker productivity loss and/or work disability to provide guidance with classification, selection, and future recommendation of outcomes. Several measurement and analytic approaches to combine absenteeism and presenteeism outcomes were proposed, and the need for further validation of such approaches was also recognized. Finally, participants at the WP-SIG were engaged to brainstorm and provide preliminary endorsements to support key contextual factors of worker productivity through an anonymous “dot voting” exercise. A total of 24 specific factors were identified, with 16 receiving ≥ 1 vote among members, reflecting highly diverse views on specific factors that were considered most important. Moving forward, further progress on these issues remains a priority to help inform the best application of worker productivity outcomes in arthritis research.