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The Work Instability Scale for Rheumatoid Arthritis (RA-WIS): Does it work in osteoarthritis?

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Abstract

Purpose

To validate the 23-item Work Instability Scale for Rheumatoid Arthritis (RA-WIS) for use in osteoarthritis (OA) using both classical test theory and item response theory approaches.

Methods

Baseline and 12-month follow-up data were collected from workers with OA recruited from community and clinical settings (n = 130). Fit of RA-WIS data to the Rasch model was evaluated by item- and person-fit statistics (size of residual, chi-sq), assessments of differential item functioning, and tests of unidimensionality and local independence. Internal consistency was assessed by KR-20. Convergent construct validity (Spearman r, known-groups) was evaluated against theoretical constructs that assess impact of health on work. Responsiveness to global indicators of change was assessed by standardized response means (SRM) and area under the receiver operating characteristic curves.

Results

Data structure of the RA-WIS showed adequate fit to the Rasch model (chi-sq = 83.2, P = 0.03) after addressing local dependency in three item pairs by creating testlets. High internal consistency (KR-20 = 0.93) and convergent validity with work-oriented constructs (|r| = 0.55–0.77) were evident. The RA-WIS correlated most strongly with the concept of illness intrusiveness (r = 0.77) and was highly responsive to changes (SRM = 1.05 [deterioration]; −0.78 [improvement]).

Conclusions

Although developed for RA, the RA-WIS is psychometrically sound for OA and demonstrates interval-level property.

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Abbreviations

RA:

Rheumatoid arthritis

OA:

Osteoarthritis

RA-WIS:

Work Instability Scale for Rheumatoid Arthritis

WI:

Work instability

IRT:

Item response theory

CI:

Confidence interval

DIF:

Differential item functioning

RUMM:

Rasch Unidimensional Measurement Models

KR-20:

Kuder-Richardson Formula 20

SRM:

Standardized response mean

ROC:

Receiver operating characteristic

AUROCC:

Area under the receiver operating characteristic curve

SAS:

Statistical analysis system

SD:

Standard deviation

HAQ:

Stanford Health Assessment Questionnaire

PSI:

Person separation index

References

  1. Badley, E. M., & Wang, P. P. (2001). The contribution of arthritis and arthritis disability to nonparticipation in the labor force: A Canadian example. Journal of Rheumatology, 28(5), 1077–1082.

    PubMed  CAS  Google Scholar 

  2. Burton, W. N., Chen, C. Y., Schultz, A. B., Conti, D. J., Pransky, G., & Edington, D. W. (2006). Worker productivity loss associated with arthritis. Disease Management, 9(3), 131–143.

    Article  PubMed  Google Scholar 

  3. Dunlop, D. D., Manheim, L. M., Yelin, E. H., Song, J., & Chang, R. W. (2003). The costs of arthritis. Arthritis and Rheumatism, 49(1), 101–113.

    Article  PubMed  Google Scholar 

  4. Gignac, M. A., Badley, E. M., Lacaille, D., Cott, C. C., Adam, P., & Anis, A. H. (2004). Managing arthritis and employment: Making arthritis-related work changes as a means of adaptation. Arthritis and Rheumatism, 51(6), 909–916.

    Article  PubMed  Google Scholar 

  5. Gignac, M. A., Sutton, D., & Badley, E. M. (2007). Arthritis symptoms, the work environment, and the future: Measuring perceived job strain among employed persons with arthritis. Arthritis and Rheumatism, 57(5), 738–747.

    Article  PubMed  Google Scholar 

  6. Lacaille, D., & Hogg, R. S. (2001). The effect of arthritis on working life expectancy. Journal of Rheumatology, 28(10), 2315–2319.

    PubMed  CAS  Google Scholar 

  7. Gilworth, G., Chamberlain, M. A., Harvey, A., Woodhouse, A., Smith, J., Smyth, M. G., et al. (2003). Development of a work instability scale for rheumatoid arthritis. Arthritis and Rheumatism, 49(3), 349–354.

    Article  PubMed  Google Scholar 

  8. Gilworth, G., Carey, A., Eyres, S., Sloan, J., Rainford, B., Bodenham, D., et al. (2006). Screening for job loss: Development of a work instability scale for traumatic brain injury. Brain Injury, 20(8), 835–843.

    Article  PubMed  Google Scholar 

  9. Gilworth, G., Bhakta, B., Eyres, S., Carey, A., Anne Chamberlain, M., & Tennant, A. (2007). Keeping nurses working: Development and psychometric testing of the Nurse-Work Instability Scale (Nurse-WIS). Journal of Advanced Nursing, 57(5), 543–551.

    Article  PubMed  Google Scholar 

  10. Stucki, G., Daltroy, L., Katz, J. N., Johannesson, M., & Liang, M. H. (1996). Interpretation of change scores in ordinal clinical scales and health status measures: The whole may not equal the sum of the parts. Journal of Clinical Epidemiology, 49(7), 711–717.

    Article  PubMed  CAS  Google Scholar 

  11. Tennant, A., & Conaghan, P. G. (2007). The Rasch measurement model in rheumatology: What is it and why use it? When should it be applied, and what should one look for in a Rasch paper? Arthritis and Rheumatism, 57(8), 1358–1362.

    Article  PubMed  Google Scholar 

  12. Rasch, G. (1960). Probabilistic models for some intelligence and attainment tests. Chicago, IL: University of Chicago Press.

    Google Scholar 

  13. Linacre, J. M. (1994). Sample size and item calibration stability. Rasch Measurement Transactions, 7, 28.

    Google Scholar 

  14. Anonymous (2009). National Occupational Classification. Human Resources and Skills Development Canada. http://www5.hrsdc.gc.ca/NOC/English/NOC/2006/Welcome.aspx. Accessed 23 May 2009.

  15. Fisher, W. J. (1992). Reliability statistics. Rasch Measurement Transactions, 6(3), 238.

    Google Scholar 

  16. Pallant, J. F., & Tennant, A. (2007). An introduction to the Rasch measurement model: An example using the Hospital Anxiety and Depression Scale (HADS). British Journal of Clinical Psychology, 46(Pt 1), 1–18.

    Article  PubMed  Google Scholar 

  17. Smith, R. M. (2000). Fit analysis in latent trait measurement models. Journal of Applied Measurement, 1(2), 199–218.

    PubMed  CAS  Google Scholar 

  18. Tennant, A., McKenna, S. P., & Hagell, P. (2004). Application of Rasch analysis in the development and application of quality of life instruments. Value in Health, 7(Suppl 1), S22–S26.

    Article  PubMed  Google Scholar 

  19. Guttman, L. A. (1950). The basis of Scalogram analysis. In J. A. Clausen (Ed.), Measurement and prediction (pp. 60–90). Princeton: Princeton University Press.

    Google Scholar 

  20. Wright, B. D. (1996). Local dependency, correlations and principal components. Rasch Measurement Transactions, 10, 509–511.

    Google Scholar 

  21. Dorans, N., & Holland, P. (1993). DIF detection and description: Mantel-Haenszel and standardisation. In H. Wainer (Ed.), Differential item functioning: Theory and practice (pp. 36–66). Hillsdale: Lawrence Erlbaum Associates.

    Google Scholar 

  22. Bland, J. M., & Altman, D. G. (1995). Multiple significance tests: The Bonferroni method. British Medical Journal, 310(6973), 170.

    PubMed  CAS  Google Scholar 

  23. Svensson, E. (2001). Guidelines to statistical evaluation of data from rating scales and questionnaires. Journal of Rehabilitation Medicine, 33(1), 47–48.

    Article  PubMed  CAS  Google Scholar 

  24. Smith, E. V. (2002). Detecting and evaluating the impact of multidimensionality using item fit statistics and principal component analysis of residuals. Journal of Applied Measurement, 3(2), 205–231.

    PubMed  Google Scholar 

  25. Tennant, A., & Pallant, J. F. (2006). Unidimensionality matters. Rasch Measurement Transactions, 20, 1048–1051.

    Google Scholar 

  26. Steinberg, L., & Thissen, D. (1996). Uses of item response theory and the testlet concept in the measurement of psychopathology. Psychological Methods, 1(1), 81–97.

    Article  Google Scholar 

  27. Thissen, D., Steinberg, L., & Mooney, J. (1989). Trace lines for testlets. Journal of Educational Measurement, 26, 247–260.

    Article  Google Scholar 

  28. Wainer, H., & Kiely, G. L. (1987). Item clusters and computer adaptive testing: A case for testlets. Journal of Educational Measurement, 24, 185–201.

    Article  Google Scholar 

  29. Hagquist, C., & Andrich, D. (2004). Is the sense of coherence-instrument applicable on adolescents? A latent trait analysis using Rasch modelling. Personality and Individual Differences, 36, 955–968.

    Article  Google Scholar 

  30. Andrich, D., Lyne, A., Sheridan, B., & Luo, G. (2003). RUMM 2020 [program]. Perth: RUMM Laboratory.

    Google Scholar 

  31. McHorney, C. A., & Tarlov, A. R. (1995). Individual-patient monitoring in clinical practice: Are available health status surveys adequate? Quality of Life Research, 4(4), 293–307.

    Article  PubMed  CAS  Google Scholar 

  32. Nunnally, J., & Bernstein, I. (1994). Psychometric theory. New York, NY: McGraw-Hill.

    Google Scholar 

  33. Terwee, C. B., Bot, S. D., de Boer, M. R., van der Windt, D. A., Knol, D. L., Dekker, J., et al. (2007). Quality criteria were proposed for measurement properties of health status questionnaires. Journal of Clinical Epidemiology, 60(1), 34–42.

    Article  PubMed  Google Scholar 

  34. Jaeschke, R., Singer, J., & Guyatt, G. H. (1989). Measurement of health status. Ascertaining the minimal clinically important difference. Controlled Clinical Trials, 10(4), 407–415.

    Article  PubMed  CAS  Google Scholar 

  35. Juniper, E. F., Guyatt, G. H., Willan, A., & Griffith, L. E. (1994). Determining a minimal important change in a disease-specific Quality of Life Questionnaire. Journal of Clinical Epidemiology, 47(1), 81–87.

    Article  PubMed  CAS  Google Scholar 

  36. Deyo, R. A., Diehr, P., & Patrick, D. L. (1991). Reproducibility and responsiveness of health status measures. Statistics and strategies for evaluation. Controlled Clinical Trials, 12(4 Suppl), 142S–158S.

    Article  PubMed  CAS  Google Scholar 

  37. Cohen, J. (1977). Statistical power analysis for the behavioral sciences. New York: Academic Press.

    Google Scholar 

  38. DeLong, E. R., DeLong, D. M., & Clarke-Pearson, D. L. (1988). Comparing the areas under two or more correlated receiver operating characteristic curves: A nonparametric approach. Biometrics, 44(3), 837–845.

    Article  PubMed  CAS  Google Scholar 

  39. Hanley, J. A., & McNeil, B. J. (1982). The meaning and use of the area under a receiver operating characteristic (ROC) curve. Radiology, 143(1), 29–36.

    PubMed  CAS  Google Scholar 

  40. Devins, G. M. (1994). Illness intrusiveness and the psychosocial impact of lifestyle disruptions in chronic life-threatening disease. Advances in Renal Replacement Therapy, 1(3), 251–263.

    PubMed  CAS  Google Scholar 

  41. Devins, G. M., Dion, R., Pelletier, L. G., Shapiro, C. M., Abbey, S., Raiz, L. R., et al. (2001). Structure of lifestyle disruptions in chronic disease: A confirmatory factor analysis of the Illness Intrusiveness Ratings Scale. Medical Care, 39(10), 1097–1104.

    Article  PubMed  CAS  Google Scholar 

  42. Tang, K., Pitts, S., Solway, S., & Beaton, D. (2009). Comparison of the psychometric properties of four at-work disability measures in workers with shoulder or elbow disorders. Journal of Occupational Rehabilitation, 19(2), 142–154.

    Article  PubMed  Google Scholar 

  43. Law, M., Baptiste, S., McColl, M., Opzoomer, A., Polatajko, H., & Pollock, N. (1990). The Canadian occupational performance measure: An outcome measure for occupational therapy. Canadian Journal of Occupational Therapy, 57(2), 82–87.

    CAS  Google Scholar 

  44. Reilly, M. C., Zbrozek, A. S., & Dukes, E. M. (1993). The validity and reproducibility of a work productivity and activity impairment instrument. Pharmacoeconomics, 4(5), 353–365.

    Article  PubMed  CAS  Google Scholar 

  45. Kessler, R. C., Barber, C., Beck, A., Berglund, P., Cleary, P. D., McKenas, D., et al. (2003). The World Health Organization Health and Work Performance Questionnaire (HPQ). Journal of Occupational & Environmental Medicine, 45(2), 156–174.

    Article  Google Scholar 

  46. van Roijen, L., Essink-Bot, M. L., Koopmanschap, M. A., Bonsel, G., & Rutten, F. F. (1996). Labor and health status in economic evaluation of health care. The Health and Labor Questionnaire. International Journal of Technology Assessment in Health Care, 12(3), 405–415.

    PubMed  Google Scholar 

  47. Fries, J. F., Spitz, P., Kraines, R. G., & Holman, H. R. (1980). Measurement of patient outcome in arthritis. Arthritis and Rheumatism, 23(2), 137–145.

    Article  PubMed  CAS  Google Scholar 

  48. Farrar, J. T., Young, J. P., Jr, LaMoreaux, L., Werth, J. L., & Poole, R. M. (2001). Clinical importance of changes in chronic pain intensity measured on an 11-point numerical pain rating scale. Pain, 94(2), 149–158.

    Article  PubMed  CAS  Google Scholar 

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Acknowledgments

Funding for the study was provided by the Canadian Arthritis Network (CAN), a Networks of Centres of Excellence, in partnership with The Arthritis Society of Canada (TAS). Funding was also received from Abbott as an unrestricted grant. The authors would like to thank the Institute for Work & Health (IWH) and the Arthritis Community Research & Evaluation Unit (ACREU) for providing in-kind support. Mr. Tang is recipient of a Canadian Institutes of Health Research (CIHR) PhD Fellowship, CAN/TAS Graduate Award, and Syme Fellowship from the IWH. Dr. Beaton was supported by a CIHR New Investigators award during the conduct of this study. Dr. Lacaille is the Nancy and Peter Paul Saunders Scholar and holds an Investigator award from TAS. Ms. Zhang is recipient of a CIHR Doctoral Research Award in the Area of Public Health Research and CAN Graduate Award. Dr. Bombardier holds a Canada Research Chair in Knowledge Transfer for Musculoskeletal Care. The authors would like to acknowledge the participating institutions where the study data were collected and research ethics board approval were obtained: the Mount Sinai Hospital, Toronto, ON (REB#05-0088-E), the Martin Family Centre for Arthritis Care and Research at St. Michael’s Hospital, Toronto, ON (REB#05-009), and the Mary Pack Arthritis Program, Vancouver, BC (REB#H05-80668) Finally, the authors wish to acknowledge the contributions from members of the Canadian Arthritis Network Work Productivity Group: Elizabeth Badley (co-investigator), Xingshan Cao (data analyst), Paul Clarke (research co-ordinator), Timea Donka (research assistant), Rebecca Dubé (research assistant), Katherine Edwards (research assistant), Taucha Inrig (research assistant), Carol Kennedy (research assistant), Jessica Lee (research co-ordinator), Xin Li (postdoctoral fellow), Samra Mian (research assistant), Ludmila Mironyuk (research co-ordinator), Anusha Raj (research associate), Pam Rogers (research co-ordinator), Rebeka Sujic (research co-ordinator), Debbie Sutton (data analyst), Ada Todd (research co-ordinator), Dwayne Van Eerd (research co-ordinator), Rebecca Wickett (research co-ordinator), and Jessica Widdifield (research co-ordinator).

Conflicts of Interest

All authors declare no conflicts of interest in relation to this work. We also declare that our funding sources had no direct role in the study design, data collection, analysis, and interpretation of the data, in the writing of the manuscript, or in the decision to publish the work.

Author information

Authors and Affiliations

  1. Mobility Program Clinical Research Unit, St. Michael’s Hospital, 30 Bond Street, Toronto, ON, M5B 1W8, Canada

    Kenneth Tang & Dorcas E. Beaton

  2. Department of Health Policy, Management and Evaluation, University of Toronto, Toronto, ON, Canada

    Kenneth Tang, Dorcas E. Beaton & Claire Bombardier

  3. Institute for Work & Health, Toronto, ON, Canada

    Kenneth Tang, Dorcas E. Beaton & Claire Bombardier

  4. Arthritis Research Centre of Canada, Vancouver, BC, Canada

    Diane Lacaille & Aslam H. Anis

  5. Division of Rheumatology, University of British Columbia, Vancouver, BC, Canada

    Diane Lacaille

  6. Toronto Western Research Institute at the University Health Network, Toronto, ON, Canada

    Monique A. M. Gignac

  7. Arthritis Community Research & Evaluation Unit, Toronto, ON, Canada

    Monique A. M. Gignac

  8. Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada

    Monique A. M. Gignac

  9. Centre for Health Evaluation & Outcome Science, St. Paul’s Hospital, Vancouver, BC, Canada

    Wei Zhang

  10. School of Population and Public Health, University of British Columbia, Vancouver, BC, Canada

    Aslam H. Anis

  11. Division of Clinical Decision Making & Health Care, Toronto General Research Institute at the University Health Network, Toronto, ON, Canada

    Claire Bombardier

  12. Division of Rheumatology, University of Toronto, Toronto, ON, Canada

    Claire Bombardier

  13. Mount Sinai Hospital, Toronto, ON, Canada

    Claire Bombardier

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  1. Kenneth Tang
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  2. Dorcas E. Beaton
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  3. Diane Lacaille
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  4. Monique A. M. Gignac
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  5. Wei Zhang
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  6. Aslam H. Anis
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  7. Claire Bombardier
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Canadian Arthritis Network Work Productivity Group

Corresponding author

Correspondence to Dorcas E. Beaton.

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Tang, K., Beaton, D.E., Lacaille, D. et al. The Work Instability Scale for Rheumatoid Arthritis (RA-WIS): Does it work in osteoarthritis?. Qual Life Res 19, 1057–1068 (2010). https://doi.org/10.1007/s11136-010-9656-y

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