Rheumatoid Arthritis-Work Instability Scale

Last Updated

November 29, 2023

Purpose

The Rheumatoid Arthritis-Work Instability Scale is an instrument to measure the risk level of work disability (WD) and assess work instability (WI) among rheumatoid arthritis patients.

Link to Instrument

https://licensing.leeds.ac.uk/product/ra-wis-early-rheumatoid-arthritis-work-instability-scale#!

Acronym RA-WIS

Area of Assessment

Occupational Performance
Functional Mobility
Activities of Daily Living
Quality of Life

Assessment Type

Patient Reported Outcomes

Cost

Free

Actual Cost

$0.00

Cost Description

Freely available for academic/research use. Charges may be applicable for commercial use.

CDE Status

Not a CDE—last searched 11/29/2023.

Musculoskeletal Conditions

Arthritis

23-items with “Yes/No” response scale
Covers broad range of specific work-related issues
Recall period of “at the moment”
Item scores summed and range from 0 to 23
Grouped into three bands (low, medium, high risk)
Higher scores reflect greater WI and higher risk for work disability
Scores greater than 17 indicate high risk for work disability
Scores between 10 and 17 indicate moderate work instability
Scores less than 10 indicate low work instability

Number of Items

5 or less minutes

Required Training

No Training

Required Training Description

Guidance notes available with registration

Adults

18 - 64

years

Elderly Adults

65 +

years

Instrument Reviewers

Mirang Park, M.S., University of Wisconsin-Madison
Sasha D. Anderson, M.S., University of Wisconsin-Madison
Susan Miller Smedema, Ph.D., CRC, LPC, University of Wisconsin-Madison
Kevin Fearn, M.S., Shirley Ryan AbilityLab

Body Part

Lower Extremity

ICF Domain

Body Function
Participation
Activity

Measurement Domain

Activities of Daily Living

Professional Association Recommendation

None found—last searched 11/29/2023.

Considerations

Responsiveness - exhibits small to moderate standardized response mean and effect size in identifying improved or deteriorated work ability (Beaton et al 2010).

Dimensionality – Gilworth et al.’s (2003) study suggested that all 23 RA-WIS items represent a single construct. In a worker population, the scale may be considered unidimensional with Rheumatoid Arthritis.

Cut-Off Scores

Rheumatoid Arthritis (RA): (Gilworth et al., 2003; n = 31 subjects who returned the original questionnaire, were employed, and who agreed to participate in a full vocational assessment; assessors were 2 professionals who were both chartered physiotherapists and registered ergonomists)

A score of 10 or more on the 23-item WI scale was shown to have 82% sensitivity to the need for workplace modifications, while a score of 17 or more gave 95% specificity. The RA-WIS can therefore be scored in 3 bands:
- <10 indicates low Work Instability (WI) and low risk of work disability (WD)
- 10 to 17 indicates moderate WI and medium risk of WD
- >17 indicates high WI and high risk of WD

Rheumatoid Arthritis (RA): (Gilworth, et al., 2009; n = 306 confirmed RA patients either in work or temporarily on sick leave (less than 6 months): French (n = 75), mean age = 46 years, female = 79%; Dutch (n = 85), mean age = 45 years, female = 73%; German (n = 73), mean age = 43 years, female = 72%; plus a randomly selected matching set (n = 73) from the original developmental study (Gilworth, et al., 2003); age = between 18 and 60 years)

Two cut points were identified for the RA-WIS: one at 10 indicating the transition from low to medium risk and the other at 17 indicating the transition from medium to high risk

Rheumatoid Arthritis (RA) or Osteoarthritis (OA): (Tang et al., 2010; n = 250 (120 with RA and 130 with OA); female:male ratio of 5:1; mean age of subgroups: OA = 54.0 (6.7), RA = 46.6 (10.2), p <0.0001; participants required to be 1) attending an outpatient rheumatology clinic with a diagnosis of OA or RA, or attending an arthritis treatment program within the past two years with a physician diagnosis of OA or RA, and 2) gainfully employed at the time or recruitment; patients followed at 3, 6, and 12 months after initial baseline; patient sampling from two tertiary-level rheumatology clinics in urban teaching hospitals (n = 142) and an outpatient arthritis treatment program providing multidisciplinary services (n = 108))

>13 is most accurate RA-WIS cut point for any form of work transition (sensitivity 51%; specificity 83%)

Rheumatoid Arthritis (RA): (Schmidt, et al., 2020; n = 140 employed patients with RA, female = 111 (79.3%), mean (SD) age = 48.7 (11.0), disease duration > 5 years from diagnosis = 114 (81.4%); physician completed Part 1 of anonymized form based on patient medical history/lab results and patient completed Part 2 of form that included an anonymous questionnaire; Polish translation of RA-WIS)

<10 indicates low Work Instability (WI)
10 to 17 indicates moderate WI
>17 indicates high WI

Normative Data

Rheumatoid Arthritis (RA): (Macedo, et al., 2009; n = 90 employed patients attending routine specialized inflammatory clinics, 70 (78%) female, mean age = 48.3 years (range = 20-69), mean disease duration (n = 86) = 9.7 (8.8) years (range = 0-38), occupational classification (n = 77) = blue collar, 10 (13%); white collar, 67 (87%))

Mean score on the Rheumatoid Arthritis-Work Instability Scale (RA-WIS, n = 90): 8.97 (6.58, range 0-22)
Mean score on the Disease Activity Score 28-joint count (DAS28, n = 80): 3.67 (1.54, range 0.8-7.00)
Mean score on the Health Assessment Questionnaire (HAQ, n = 79): 0.90 (0.74, range 0-2.63)

Rheumatoid Arthritis (RA) or Osteoarthritis (OA): (Beaton et al., 2010; n = 250 (120 with RA and 130 with OA), female = 82.7%, mean age = 50.6 (9.2), 54.7% diagnosed with arthritis for >5 years 9.8% diagnosed for <1 year, patients followed at 3, 6, and 12 months after initial baseline, patient sampling from two tertiary-level rheumatology clinics in urban teaching hospitals (n = 142) and an outpatient arthritis treatment program providing multidisciplinary services (n = 108)

Mean score on the RA-WIS (n = 223): 8.3 (6.4)

Early Rheumatoid Arthritis (RA): (Revicki et al., 2015; n = 148, mean age = 46.8 years, female = 83 (56.1%), data from 56-week, randomized control trial of patients with early RA with data collected at baseline and at weeks 12, 16, 24, and 56)

Mean score on the RA-WIS (n = 148): 15.3 (5.5)

Rheumatoid Arthritis (RA): (Schmidt, et al., 2020)

Mean score on the RA-WIS (n = 140) = 13.45 (6.14)

Test/Retest Reliability

Rheumatoid Arthritis (RA): (Gilworth et al., 2003; n = 51 (41% of the 123 subjects who returned both questionnaires sent at 2-week intervals to 229 potential subjects)

Acceptable test-retest reliability: (Spearman’s rho = 0.89)

Early Rheumatoid Arthritis (RA): (Revicki et al., 2015; n = 148)

Excellent test-retest reliability: (ICC = 0.91)

Internal Consistency

Rheumatoid Arthritis (RA): (Gilworth, et al., 2009; n = 306)

Excellent overall Person Separation Index (PSI) on RA-WIS for all countries = 0.914
- Excellent PSI values on RA-WIS by country: UK (0.928), Dutch (0.930), German (0.917), and French (0.898)
- The consistently high PSI values throughout the analyses of the data for the RA-WIS resulted in the determination that the measure was suitable for individual use.

Rheumatoid Arthritis (RA) or Osteoarthritis (OA): (Beaton et al., 2010)

Excellent: Cronbach’s alpha (n = 223) = 0.92*

Early Rheumatoid Arthritis (RA): (Revicki et al., 2015; n = 148)

Excellent: Cronbach’s alpha = 0.89

*Scores higher than 0.9 may indicate redundancy in the scale questions.

Criterion Validity (Predictive/Concurrent)

Predictive validity

Higher baseline RA-WIS (RR = 1.05 [95% CI 1.00-1.11] per unit increase in score) was predictive of impending arthritis-related work transitions (i.e. permanent reductions in work hours, disability {sick} leaves of absence, changes in occupation or job, or temporary unemployment {became unemployed but looking for work}) after controlling for pain intensity and arthritis diagnosis as the only covariates retained.
- A significant interaction effect (p = 0.04) was found between RA-WIS and pain intensity, with the RA-WIS having significant associations with the outcome at higher levels of pain, but not at lower levels of pain.
The RA-WIS was not found to be a predictor or covariate for any of the secondary outcomes relating to decreases in perceived work capacity

Rheumatoid Arthritis (RA): (Macedo, et al., 2009)

A Disease Activity Score 28-joint count (DAS28) of greater than 3.81 combined with a Health Assessment Questionnaire (HAQ) score greater than 0.55 characterized the moderate-high RA-WIS (>= 10) group with high sensitivity (0.90) and specificity (0.76) and had the strongest overall association with moderate-high RA-WIS (OR = 29.87)

Rheumatoid Arthritis (RA): (Schmidt, et al., 2020)

Significant differences among employed patients with low-to-moderate and high RA-WIS scores on various clinical characteristics

Clinical characteristics of employed patients according to work instability risk, mean (SD)

Characteristic	Low-to-moderate RA-WIS (0-17)	High RA-WIS (>17)
ESR (mm/h)	18.3 (16)	28.2 (21.9)*
CRP (mg/dl)	0.6 (1.0)	1.1 (1.0)*
Tender joint count	4.5 (4.0)	7.6 (6.3)*
Swollen joint count	2.7 (3.0)	5.2 (5.5)*
HAQ-DI	0.7 (0.5)	1.1 (0.5)*
Pain – VAS 10 cm	3.9 (1.9)	6.5 (2.2)*
DAS28	3.5 (1.2)	4.2 (1.4)*
DAS28-CRP	3.9 (1.0)	4.3 (1.2)*

ESR – erythrocyte sedimentation rate, CRP – C-reactive protein, HAQ-DI – Health Assessment Questionnaire Disability Index, VAS – Visual Analogue Scale, DAS28 – Disease Activity Score in 28 joints.

*p < 0.05, Mann-Whitney U test

Construct Validity

Convergent validity

Early Rheumatoid Arthritis (RA): (Revicki et al., 2015; n = 148)

Adequate to Excellent convergent validity between RA-WIS and Duration of morning stiffness, the Health Assessment Questionnaire-Disability Index (HAQ-DI), the 28-Joint Disease Activity Scale (DAS28), the Patient Global Assessment of Disease Activity, the Patient Assessment of Pain, the RA Quality of Life Questionnaire (RAQoL), the Swollen joint count (SJC28), the Tender joint count (TJC28), the Number of hours lost per week because of RA, the Number of hours lost per week, the Number of hours worked per week, and the effect of RA on work performance

Measure	RA-WIS at Week 0	RA-WIS at Week 24
Duration of morning stiffness	0.31^a	0.36^b
HAQ-DI	0.55^c	0.76^c
DAS28	0.37^c	0.55^c
Patient Global Assessment of Disease Activity	0.47^c	0.66^c
Patient Assessment of Pain	0.55^c	0.62^c
Physician Global Assessment of Disease Activity	0.31^a	0.52^c
RAQoL	0.77^c	0.81^c
SJC28	0.07	0.46^c
TJC28	0.35^c	0.55^c
No. of hours lost per week because of RA	0.37^c	0.27^b
No. of hours lost per week	0.30^a	0.09
No. of hours worked per week	-0.09	-0.12
Effect of RA on work performance	0.37^c	0.64^c

^ap < 0.001

^bp < 0.05

^cp < 0.0001

“Rasch model, which identified 23 items on a single construct of WI that were free from item bias for age and sex. Fit to the model was confirmed by excellent item fit (mean = 0.056, SD = 0.092) and person fit (mean = −0.062, SD = 0.595) statistics. Item trait interaction chi‐square of 34.1, (degrees of freedom (df) = 46; P = 0.90) showed the classic property of invariance for the scale.”

Rheumatoid Arthritis (RA): (Gilworth, et al., 2009; n = 306)

The data from the four countries (UK, Dutch, German, French) pooled together showed good fit to the Rasch model (item fit mean = -0.168, SD = 1.277, person fit mean = −0.197, SD = 0.739, interaction chi-square = 133.5 (df = 92), p < 0.003) and demonstrated strict unidimensionality.
Individual country data also showed good fit to the Rasch model, with the exception of France, where one item—“Au travail, j’ai des jours avec et des jours sans” (I get good days and bad days at work)—showed significant misfit to the expectation of the model. Fit to the model expectation was good following the removal of this item.
Differential item functioning (DIF) by country was found to be present for six of the items. However, the DIF appeared to both cancel out at the test level in the pooled data, and impact the test score itself only marginally.

Rheumatoid Arthritis (RA): (Macedo, et al., 2009)

Adequate convergent validity with DAS28 (r = 0.53)
Excellent convergent validity with HAQ (r = 0.66)
DAS, HAQ, and sex explained 54% of the variability in RA-WIS scores (R² = 0.57; adjusted R² = 0.54)

Rheumatoid Arthritis (RA) or Osteoarthritis (OA): (Beaton et al., 2010)

Correlations of RA-WIS with various theoretical constructs (n=223)

Theoretical constructs (a priori hypothesized relationship)	RA-WIS
Work-oriented constructs
Self-rated work productivity (r < -0.5)	-0.54^a
Perceived impact of health problems on work (r > 0.5)	0.73^a
Self-rated difficulty doing work (r > 0.75)	0.71
Satisfaction with occupational performance (r < -0.75)	-0.68
Self-rated ability to work (r < -0.75)	-0.67
Intrusion of arthritis on work ability (r > 0.75)	0.74
Self-rated job performance in past week (r < -0.5)	-0.56^a
Arthritis hindrance on work performance^b	105.1^c
Disease-oriented constructs
General perceived disability (r > 0.5)	0.66^a
Arthritis severity (r > 0.5)	0.62^a
Pain intensity over past week (r > 0.5)	0.67^a

^aA priori hypothesis met.

^bF values from analysis of variance between known groups {[0, no] vs. [1, to a degree] vs. [2, very much] were reported.

^cTukey P < 0.05 for all t-test comparisons (i.e. 0 vs. 1, 1 vs. 2, 0 vs. 2) and evidence of logical gradient.

RA-WIS correlated to the largest number of constructs (7 out of 11) above the hypothesized level compared to 8 other scales
RA-WIS also exhibited the strongest known-group validity (F = 105.1 vs. F = 9.5 – 68.9 for the other scales) in differentiating workers experiencing varying levels of arthritis-related hindrance on work performance
Adequate to Excellent convergent validity of the RA-WIS with other measures of at-work productivity in workers with arthritis (|r| = 0.41-0.77)

Rheumatoid Arthritis (RA): (Schmidt, et al., 2020)

Adequate convergent validity of the RA-WIS with the Visual Analogue Scale (r = 0.59, p < 0.001), the Health Assessment Questionnaire Disability Index (r = 0.52, p < 0.001), and the Disease Activity Score in 28 joints (r = 0.31, p < 0.001)
Poor convergent validity of the RA-WIS with the DAS28-C-Reactive Protein (r = 0.28, p < 0.001)

Face Validity

Rheumatoid Arthritis (RA): (Gilworth, et al., 2009; n = 306)

The RA-WIS questionnaires in the UK, Dutch, German, & French versions were field tested for face validity
- The questionnaires were largely judged to be understandable and patients stated that the RA-WIS covered notions that were important for them
- The clarity and wording of the instructions were also deemed to be easily understood and there were no modifications of instruction or question phrasing at this stage

Responsiveness

Rheumatoid Arthritis (RA) or Osteoarthritis (OA): (Beaton et al., 2010)

The RA-WIS ranked second overall (to the Workplace Activity Limitations Scale or WALS) and no worse than second in 5 of 7 criteria related to the responsiveness to change in work ability
The RA-WIS ranked last overall in terms of responsiveness to change in work productivity, especially for deteriorations where it ranked last for effect size, standardized response mean, and Spearman’s r

Early Rheumatoid Arthritis (RA): (Revicki et al., 2015; n = 148)

Significantly different RA-WIS total change scores among American College of Rheumatology (ACR) classification groups from mean baseline to week 24 and from baseline to week 56 (p < 0.0001)
- Greatest differences at week 24 observed between responder groups with improvements of less than 20% and those with 20% to less than 50% (5.01 points)
- Greatest differences at week 56 observed between responder groups with improvements of 20% to less than 50% and those with 50% to less than 70% (4.35 points)
Significantly different RA-WIS total change scores based upon DAS28 remission status, with larger changes from baseline to week 24 observed for patients in remission (DAS28 < 2.6) than in those not in remission (DAS28 => 2.6, p < 0.001), with similar findings in RA-WIS total change scores from baseline to week 56 (p < 0.0001)
- Differences between remission and non-remission groups were 5.14 points at week 24 and 3.48 points at week 56

Standard Error of Measurement (SEM)

Fibromyalgia: (Hammond et al., 2023; Phase 2: n = 156 persons with primary diagnosis of fibromyalgia; female = 146 (94%); mean age (years (SD)) = 45.71 (10.05); SEM = Standard Deviation from the first test x (square root of (1-ICC))

SEM = 1.20

Minimal Detectable Change (MDC)

Fibromyalgia: (Hammond et al., 2023; Phase 2: n = 156 persons with primary diagnosis of fibromyalgia; MDC = SEM x 1.96 x square root of 2)

MDC = 3.38

Test/Retest Reliability

Fibromyalgia: (Hammond et al., 2023; Phase 2: n = 156 persons with primary diagnosis of fibromyalgia)

Excellent test-retest reliability among participants reporting their health “the same as at T1” at T2: (ICC = 0.90)

Internal Consistency

Fibromyalgia: (Hammond et al., 2023; Phase 2: n = 156 persons with primary diagnosis of fibromyalgia)

Adequate: Cronbach’s alpha = 0.78

Criterion Validity (Predictive/Concurrent)

Concurrent validity:

Fibromyalgia: (Hammond et al., 2023; Phase 2: n = 156 persons with primary diagnosis of fibromyalgia)

Adequate to Excellent concurrent validity between the rheumatoid arthritis (RA) Work Instability Scale (WIS) and work and health measures in fibromyalgia (FM)

RA-WIS correlations with:	FM (n = 156) r
Work measures:
Work Limitations Questionnaire-25 (0-100)
Time management demands	0.61*
Physical demands	0.32*
Mental interpersonal demands	0.61*
Output demands	0.58*
WLQ-25% productivity loss	0.66*
WLQ-25 summed score	0.66*
Workplace Activity Limitations Scale	0.60*
Workplace Productivity Activity Impairment Scale
Overall work impairment due to health	0.56*
Work self-efficacy	0.55*
Health measures
Fibromyalgia Impact Questionnaire-Revised (normalized scores)
Overall impact (0-20)	0.47*
Symptoms (0-50)	0.54*
Function (0-30)	0.40*
FIQ-R total (0-100)	0.56*

*Excellent: r = >=0.6; Adequate: r = 0.31 – 0.59

Construct Validity

Construct validity:

Fibromyalgia: (Hammond et al., 2023; Phase 2: n = 156 persons with primary diagnosis of fibromyalgia)

After grouping three clusters of locally dependent items (involving 8 of the 23 items) into super items and refitting to the Rasch model, a satisfactory result that included unidimensionality was obtained that explained 95% of the variance.

Discriminant validity:

Fibromyalgia: (Hammond et al., 2023; Phase 2: n = 156 persons with primary diagnosis of fibromyalgia)

Significant differences in mean RA-WIS scores between subjects with differing levels of self-reported health

Self-reported health	n	Mean RA-WIS Score (range)
Poor/very poor	83	19.00 (17.00-20.00)
Fair	63	17.00 (13.00-19.00)
Good/very good	10	13.50 (9.25-16.50)

H = 27.17, p < 0.001

Content Validity

Fibromyalgia: (Hammond et al., 2023; Phase 1: Cognitive debriefing interviews with 13 persons with primary diagnosis of fibromyalgia; female = 11 (85%); mean age (years (SD)) = 39.69 (9.11))

Nearly all participants considered every item very or extremely relevant.
All participants considered that the main work issues relevant to them were included in the RA-WIS.
All participants stated that the RA-WIS was easy to understand and complete.

Floor/Ceiling Effects

Fibromyalgia: (Hammond et al., 2023; Phase 2: n = 156 persons with primary diagnosis of fibromyalgia)

Excellent: no floor effects
Adequate ceiling effect of 5.77%

Bibliography

Beaton, D. E., Tang, K., Gignac, M. A., Lacaille, D., Badley, E. M., Anis, A. H., & Bombardier, C. (2010). Reliability, validity, and responsiveness of five at‐work productivity measures in patients with rheumatoid arthritis or osteoarthritis. Arthritis Care & Research: Official Journal of the American College of Rheumatology, 62(1), 28-37.

Fabreguet, I., Koumakis, E., Burki, V., Durnez, A., Elhai, M., Meyer, M., Paternotte, S., Payet, J., Roure, F., & Fautrel, B., Dougados, M., Dougados, M., & Gossec, L. (2012). Assessment of work instability in spondyloarthritis: a cross-sectional study using the ankylosing spondylitis work instability scale. Rheumatology, 51(2), 333-337.

Gilworth, G., Chamberlain, M. A., Harvey, A., Woodhouse, A., Smith, J., Smyth, M. G., & Tennant, A. (2003). Development of a work instability scale for rheumatoid arthritis. Arthritis Care & Research, 49(3), 349-354.

Gilworth, G., Emery, P., Gossec, L., Vliet Vlieland, T.P.M., Breedveld, F.C., Hueber, A.J., Schett, G., & Tennant, A. (2009). Adaptation and cross-cultural validation of the rheumatoid arthritis work instability scale (RA-WIS). Annals of the Rheumatic Diseases, 68: 1686-1690. https://doi.org/10.1136/ard.2008.098921

Hammond, A., Tennant, A., Brown, T., Prior, Y., Ching, A., & Parker, J. (2023). Psychometric testing of the Rheumatoid Arthritis Work Instability Scale in employed people with fibromyalgia. Musculoskeletal Care, 1-13, https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/msc.1829

Macedo, A. M., Oakley, S. P., Gullick, N. J., & Kirkham, B. W. (2009). An examination of work instability, functional impairment, and disease activity in employed patients with rheumatoid arthritis. The Journal of Rheumatology, 36(2), 225-230, doi: https://doi.org/10.3899/jrheum.071001

McFadden, E., Horton, M. C., Ford, H. L., Gilworth, G., McFadden, M., & Tennant, A. (2012). Screening for the risk of job loss in multiple sclerosis (MS): development of an MS-specific Work Instability Scale (MS-WIS). Multiple Sclerosis Journal, 18(6), 862-870.

Revicki, D., Ganguli, A., Kimel, M., Roy, S., Chen, N., Safikhani, S., & Cifaldi, M. (2015). Reliability and validity of the work instability scale for rheumatoid arthritis. Value in Health, 18(8), 1008-1015.

Schmidt, W., Tapolska, M., Pawlak-Bus, K., Owczarek, M., Leszczynski, P. (2020). Work instability and associated factors among patients with rheumatoid arthritis in Greater Poland. Reumatologia, 58(4): 208-212, doi: https://doi.org/10.5114/reum.2020.98432

Tang, K., Beaton, D. E., Lacaille, D., Gignac, M. A., Zhang, W., Anis, A. H., Bombardier, C., & Canadian Arthritis Network Work Productivity Group. (2010). The Work Instability Scale for Rheumatoid Arthritis (RA-WIS): does it work in osteoarthritis? Quality of Life Research, 19(7), 1057-1068.

Tang, K., Beaton, D. E., Gignac, M. A., Lacaille, D., Zhang, W., & Bombardier, C. (2010). The Work Instability Scale for rheumatoid arthritis predicts arthritis‐related work transitions within 12 months. Arthritis care & research, 62(11), 1578-1587.

Last Updated

Purpose

Link to Instrument

Area of Assessment

Assessment Type

Cost

Actual Cost

Cost Description

CDE Status

Number of Items

Required Training

Required Training Description

Instrument Reviewers

Body Part

ICF Domain

Measurement Domain

Professional Association Recommendation

Considerations

Cut-Off Scores

Normative Data

Test/Retest Reliability

Internal Consistency

Criterion Validity (Predictive/Concurrent)

Construct Validity

Face Validity

Responsiveness

Standard Error of Measurement (SEM)

Minimal Detectable Change (MDC)

Test/Retest Reliability

Internal Consistency

Criterion Validity (Predictive/Concurrent)

Construct Validity

Content Validity

Floor/Ceiling Effects

Bibliography

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