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Comparative Study
. 2010 Apr;37(4):717-22.
doi: 10.3899/jrheum.090764. Epub 2010 Mar 1.

Comparison of the construct validity and sensitivity to change of the visual analog scale and a modified rating scale as measures of patient global assessment in rheumatoid arthritis

Chili Lati  1 , Lori C Guthrie, Michael M Ward
Affiliations
Comparative Study

Comparison of the construct validity and sensitivity to change of the visual analog scale and a modified rating scale as measures of patient global assessment in rheumatoid arthritis

Chili Lati et al. J Rheumatol. 2010 Apr.

Abstract

Objective: Patient global assessment (PGA) is commonly measured using a visual analog scale (VAS). The VAS asks patients to integrate many dimensions of rheumatoid arthritis (RA) activity, yet its scope is poorly defined and its endpoints are vague. We investigated whether a modified Rating Scale that used marker states and more defined endpoints would provide a more valid measure of PGA.

Methods: In our prospective longitudinal study, 164 patients with active RA rated their global arthritis activity using the VAS and Rating Scale before and after treatment. To compare construct validity, we correlated each score with 2 reference measures of RA activity, the 28-joint count Disease Activity Score (DAS28) and the physician global assessment, and examined how each measure was associated with different aspects of RA activity, including pain, functioning, and depressive symptoms, in multivariate regression analyses. We also examined sensitivity to change.

Results: Both measures were correlated with the DAS28 (r = 0.39 for VAS; r = 0.35 for Rating Scale) and physician global assessment (r = 0.41 for VAS; r = 0.26 for Rating Scale) at the baseline visit. Pain and depressive symptoms had the strongest association with the VAS, while functional limitations and depressive symptoms had the strongest association with the Rating Scale. Residual analysis showed no differences in heterogeneity of patients' ratings. VAS was more sensitive to change than the Rating Scale (standardized response means of 0.55 and 0.45).

Conclusion: As measures of PGA, the VAS and Rating Scale had comparable construct validity, but differed in which aspects of arthritis activity influenced scores. VAS was more sensitive to change.

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References

    1. Felson DT, Anderson JJ, Boers M. The American College of Rheumatology preliminary core set of disease measures for rheumatoid arthritis clinical trials. The Committee on Outcome Measures in Rheumatoid Arthritis Clinical Trials. Arthritis Rheum. 1993;36:729–40. - PubMed
    1. Scott DL, van Riel PLCM, van der Heijde D. On behalf of the EULAR standing Committee for International Clinical Case Studies Including Therapeutic Trials — ESCISIT. Zurich: EULAR; 1993. Assessing disease activity in rheumatoid arthritis — The EULAR handbook of standard methods.
    1. Boers M, Tugwell P, Felson DT, van Riel PL, Kirwan JR, Edmonds JP, et al. World Health Organization and International League of Associations for Rheumatology core endpoints for symptom modifying antirheumatic drugs in rheumatoid arthritis clinical trials. J Rheumatol. 1994;21 (Suppl 41):86–9. - PubMed
    1. Ward MM. Clinical measures in rheumatoid arthritis: which are most useful in assessing patients? J Rheumatol. 1994;21:17–27. - PubMed
    1. Gill TM, Feinstein AR. A critical appraisal of the quality of quality-of-life measurements. JAMA. 1994;272:619–26. - PubMed

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