Article Text

PDF
FRI0367 Fatigue is an Internationally Valid Concept: The Bristol RA Fatigue Multi-Dimensional Questionnaire (BRAF-MDQ) in 6 EU Countries
  1. S. Hewlett1,
  2. J. Nicklin1,
  3. J. Kirwan2,
  4. F. Cramp1,
  5. E. Dures1,
  6. R. Greenwood3,
  7. J. Fransen4,
  8. M. Englbrecht5,
  9. G. Schett5,
  10. I. Petersson6,
  11. S. Hagel6,
  12. L. Carmona7,
  13. M. Redondo8,
  14. A. Molto9,
  15. C. Bode10,
  16. M. van de Laar10,
  17. L. Gossec9
  18. on behalf of EULAR BRAF-RAID working group
  1. 1University of the West of England
  2. 2University of Bristol
  3. 3University Hospitals, Bristol, United Kingdom
  4. 4Radboud University, Nijmegen, Netherlands
  5. 5Friedreich Alexander University, Erlangen, Germany
  6. 6Lund University, Lund, Sweden
  7. 7Instituto de Salud Musculoesquelética
  8. 8Universidad Camilo José Cela, Madrid, Spain
  9. 9Sorbonne Universités, Paris, France
  10. 10University of Twente, Enschede, Netherlands

Abstract

Background The 20-item BRAF-MDQ was developed in the UK to measure RA fatigue, with a total score and 4 distinct subscales reflecting different fatigue concepts; there are 35 translations. If the translations adequately capture these concepts, then their internal factor structure should be similar; if not this would indicate important cultural differences in fatigue perception, requiring country-specific scoring. Criterion and construct validity have not yet been examined outside the UK.

Objectives To test the internal structure, criterion and construct validity of the BRAF-MDQ in France (F), Germany (G), Netherlands (N), Spain (Sp), Sweden (Sw) and UK.

Methods 100-200 RA patients in each country completed the BRAF-MDQ (sufficient for reliable factor analysis by country), the RA Impact of Disease (RAID) and the SF-36. BRAF-MDQ internal factor structure was tested by confirmatory factor analysis of the original 4 factors; internal consistency by Cronbach's alpha; criterion validity by Spearman's correlation with RAID and SF-36 vitality subscale; and construct validity by correlation with the remaining 7 SF-36 domains.

Results 1276 patients participated (F 206, G 216, N 317, Sp 157, Sw 170, UK 210). Overall, 76% were female; 10% <40 yrs old and 50% ≥60 yrs; 25.5% disease duration <5 yrs, with no major differences between countries. Overall mean BRAF-MDQ (0-70) was 26.04 (SD 16.18, range 0-70), country range 22.02 (G) to 34.19 (UK).

The original 4-factor structure was upheld in each country with all items loading >0.7: Physical fatigue factor 0.749-0.910, Living with fatigue 0.705-0.899, Cognitive fatigue 0.797-0.959 and Emotional fatigue 0.793-0.919. The factor structure was upheld in 476/480 further tests comprising the 4 factors tested in 20 randomly selected subsets of 50% of patients per country (bootstrapping).

Internal consistency was strong in all 6 countries for the total BRAF-MDQ: Cronbach's alpha 0.932-0.954. Subscales were also internally consistent in all 6 countries: Physical 0.75-0.791; Living 0.918-0.943; Cognition 0.912-0.955, Emotion 0.852-0.893.

Criterion validity was shown in the toal sample and all 6 countries by high correlations amongst the BRAF subscales (0.367-0.986); high correlations of the total BRAF with the BRAF subscales (r=0.815–0.928); and of the total BRAF and subscales with both the RAID fatigue item (0.512-0.878) and SF-36 Vitality item (-0.501 to -0.830).

Construct validity was shown in all 6 countries and in the total sample by appropriate correlations between the total BRAF, subscales and the remaining 7 SF-36 health domains: r=-0.223 (Sw, Emotion with Physical Function) to -0.760.

Conclusions The BRAF-MDQ has an internal factor structure that holds across 6 EU countries, supporting its conceptual validity internationally. It has evidence for internal consistency, criterion and construct validity in 6 countries, further supporting its increasingly widespread use.

Disclosure of Interest None declared

Statistics from Altmetric.com

Request permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.